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  • Samba users not added untill they logon first? Edit: How do I add users to tdbsam without a password prompt?

    - by glisignoli
    I add users to my server with the command useradd -m -p PASS_HASH -s /usr/sbin/nologin USERNAME Then I try to access their samba home share, but it never shows up until I login with the user: root:~$sudo login failtest Password:###### Added user failtest. Is there some way of added the user without logging in? Edit: The problem is that the user is added with the useradd command, but ubuntu seems to run an initalisation script when the user logs on for the first time. This script then adds that user to the tdbsam user database. Finding the initalisation script or the method it uses to add a user to the tdbsam database without requiring any user input (as smbpasswd -a USER prompts the user for a password). So all I need is a way to add a user+pass to the tdbsam database without prompting a user for a password (eg: samaba-add-user.sh USERNAME PASSWORD).

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  • Squid - Logging to MySQL without empty rows/skipped records?

    - by Lee Ward
    I'm trying to figure out how to make Squid proxy log to MySQL. I know ACL order is pretty important but I'm not sure if I understand exactly what ACLs are or do, it's difficult to explain, but hopefully you'll see where I'm going with this as you read! I have created the lines to make Squid interact with a helper in squid.conf as follows: external_acl_type mysql_log %LOGIN %SRC %PROTO %URI php /etc/squid3/custom/mysql_lg.php acl ex_log external mysql_log http_access allow ex_log The external ACL helper (mysql_lg.php) is a PHP script and is as follows: error_reporting(0); if (! defined(STDIN)) { define("STDIN", fopen("php://stdin", "r")); } $res = mysql_connect('localhost', 'squid', 'testsquidpw'); $dbres = mysql_select_db('squid', $res); while (!feof(STDIN)) { $line = trim(fgets(STDIN)); $fields = explode(' ', $line); $user = rawurldecode($fields[0]); $cli_ip = rawurldecode($fields[1]); $protocol = rawurldecode($fields[2]); $uri = rawurldecode($fields[3]); $q = "INSERT INTO logs (id, user, cli_ip, protocol, url) VALUES ('', '".$user."', '".$cli_ip."', '".$protocol."', '".$uri."');"; mysql_query($q) or die (mysql_error()); if ($fault) { fwrite(STDOUT, "ERR\n"); }; fwrite(STDOUT, "OK\n"); } The configuration I have right now looks like this: ## Authentication Handler auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp auth_param ntlm children 30 auth_param negotiate program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic auth_param negotiate children 5 # Allow squid to update log external_acl_type mysql_log %LOGIN %SRC %PROTO %URI php /etc/squid3/custom/mysql_lg.php acl ex_log external mysql_log http_access allow ex_log acl localnet src 172.16.45.0/24 acl AuthorizedUsers proxy_auth REQUIRED acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl CONNECT method CONNECT acl blockeddomain url_regex "/etc/squid3/bl.acl" http_access deny blockeddomain deny_info ERR_BAD_GENERAL blockeddomain # Deny requests to certain unsafe ports http_access deny !Safe_ports # Deny CONNECT to other than secure SSL ports http_access deny CONNECT !SSL_ports # Allow the internal network access to this proxy http_access allow localnet # Allow authorized users access to this proxy http_access allow AuthorizedUsers # FINAL RULE - Deny all other access to this proxy http_access deny all From testing, the closer to the bottom I place the logging lines the less it logs. Oftentimes, it even places empty rows in to the MySQL table. The file-based logs in /var/log/squid3/access.log are correct but many of the rows in the access logs are missing from the MySQL logs. I can't help but think it's down to the order I'm putting lines in because I want to log everything to MySQL, unauthenticated requests, blocked requests, which category blocked a specific request. The reason I want this in MySQL is because I'm trying to have everything managed via a custom web-based frontend and want to avoid using any shell commands and access to system log files if I can help it. The end result is to make it as easy as possible to maintain without keeping staff waiting on the phone whilst I add a new rule and reload the server! Hopefully someone can help me out here because this is very much a learning experience for me and I'm pretty stumped. Many thanks in advance for any help!

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  • Unable to have nokogiri obey custom path parameters during install

    - by Christopher
    I am trying to install nokogiri locally on dreamhost using the commands: $ wget ftp://xmlsoft.org/libxml2/libxml2-2.7.6.tar.gz $ wget ftp://xmlsoft.org/libxml2/libxslt-1.1.26.tar.gz $ tar zxvf libxml2-2.7.6.tar.gz $ cd libxml2-2.7.6 $ ./configure --prefix=$HOME/local/ --exec-prefix=$HOME/local $ make && make install $ cd .. $ tar zxvf libxslt-1.1.26.tar.gz $ cd libxslt-1.1.26 $ ./configure --prefix=$HOME/local/ --with-libxml-prefix=$HOME/local/ $ make && make install $ export LD_LIBRARY_PATH=$HOME/local/lib $ gem install nokogiri -- --with-xslt-dir=$HOME/local \ --with-xml2-include=$HOME/local/include/libxml2 \ --with-xml2-lib=$HOME/local/lib but it still gives the error: Building native extensions. This could take a while... ERROR: Error installing nokogiri: ERROR: Failed to build gem native extension. /usr/bin/ruby1.8 extconf.rb checking for iconv.h in /opt/local/include/,/opt/local/include/libxml2,/opt/local/include,/opt/local/include,/opt/local/include/libxml2,/usr/local/include,/usr/local/include/libxml2,/usr/include,/usr/include/libxml2,/usr/include,/usr/include/libxml2... yes checking for libxml/parser.h in /opt/local/include/,/opt/local/include/libxml2,/opt/local/include,/opt/local/include,/opt/local/include/libxml2,/usr/local/include,/usr/local/include/libxml2,/usr/include,/usr/include/libxml2,/usr/include,/usr/include/libxml2... yes checking for libxslt/xslt.h in /opt/local/include/,/opt/local/include/libxml2,/opt/local/include,/opt/local/include,/opt/local/include/libxml2,/usr/local/include,/usr/local/include/libxml2,/usr/include,/usr/include/libxml2,/usr/include,/usr/include/libxml2... no libxslt is missing. try 'port install libxslt' or 'yum install libxslt-devel' *** extconf.rb failed *** Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options. Provided configuration options: --with-opt-dir --without-opt-dir --with-opt-include --without-opt-include=${opt-dir}/include --with-opt-lib --without-opt-lib=${opt-dir}/lib --with-make-prog --without-make-prog --srcdir=. --curdir --ruby=/usr/bin/ruby1.8 --with-iconv-dir --without-iconv-dir --with-iconv-include --without-iconv-include=${iconv-dir}/include --with-iconv-lib --without-iconv-lib=${iconv-dir}/lib --with-xml2-dir --without-xml2-dir --with-xml2-include --without-xml2-include=${xml2-dir}/include --with-xml2-lib --without-xml2-lib=${xml2-dir}/lib --with-xslt-dir --without-xslt-dir --with-xslt-include --without-xslt-include=${xslt-dir}/include --with-xslt-lib --without-xslt-lib=${xslt-dir}/lib Gem files will remain installed in /home/myusername/.gems/gems/nokogiri-1.4.1 for inspection. Results logged to /home/myusername/.gems/gems/nokogiri-1.4.1/ext/nokogiri/gem_make.out where it doesn't seem to be looking in the paths I have specified for the libraries. Is there something wrong with my installation method?

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  • How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?

    - by Philip Durbin
    Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized: [root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen May 5 16:54:35 fs-2 kernel: ata1: SError: { PHYRdyChg CommWake } May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset May 5 16:54:45 fs-2 kernel: ata1: soft resetting link May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:54:55 fs-2 kernel: ata1: soft resetting link May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:05 fs-2 kernel: ata1: soft resetting link May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps May 5 16:55:40 fs-2 kernel: ata1: soft resetting link May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up May 5 16:55:45 fs-2 kernel: ata1: EH complete I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn't work: [root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan -bash: echo: write error: Invalid argument [root@fs-2 ~]# [root@fs-2 ~]# /root/rescan-scsi-bus.sh -l [snip] 0 new device(s) found. 0 device(s) removed. [root@fs-2 ~]# [root@fs-2 ~]# ls /dev/sda ls: /dev/sda: No such file or directory I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting? The operating system in question is RHEL5.3: [root@fs-2 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.3 (Tikanga) The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS. Here is the lscpi output: [root@fs-2 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) Update: In perhaps a dozen cases, we've been forced to reboot servers because hot swap hasn't "just worked." Thanks for the answers to look more into the SATA controller. I've included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn't supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful. The good news is that hot swap "just worked" today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output: [root@www-1 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)

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  • How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?

    - by Philip Durbin
    Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn't recognized: [root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen May 5 16:54:35 fs-2 kernel: ata1: SError: { PHYRdyChg CommWake } May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset May 5 16:54:45 fs-2 kernel: ata1: soft resetting link May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:54:55 fs-2 kernel: ata1: soft resetting link May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:05 fs-2 kernel: ata1: soft resetting link May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps May 5 16:55:40 fs-2 kernel: ata1: soft resetting link May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up May 5 16:55:45 fs-2 kernel: ata1: EH complete I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn't work: [root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan -bash: echo: write error: Invalid argument [root@fs-2 ~]# [root@fs-2 ~]# /root/rescan-scsi-bus.sh -l [snip] 0 new device(s) found. 0 device(s) removed. [root@fs-2 ~]# [root@fs-2 ~]# ls /dev/sda ls: /dev/sda: No such file or directory I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting? The operating system in question is RHEL5.3: [root@fs-2 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.3 (Tikanga) The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS. Here is the lscpi output: [root@fs-2 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) Update: In perhaps a dozen cases, we've been forced to reboot servers because hot swap hasn't "just worked." Thanks for the answers to look more into the SATA controller. I've included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn't supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful. The good news is that hot swap "just worked" today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output: [root@www-1 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)

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  • C# Regex - Replace multiple characters at once without overwriting?

    - by Everaldo Aguiar
    Hello guys, I'm implementing a c# program that should automatize a Mono-alphabetic substitution cipher. The functionality i'm working on at the moment is the simplest one: The user will provide a plain text and a cipher alphabet, for example: Plain text(input): THIS IS A TEST Cipher alphabet: A - Y, H - Z, I - K, S - L, E - J, T - Q Cipher Text(output): QZKL KL QJLQ I thought of using regular expressions since I've been programming in perl for a while, but I'm encountering some problems on c#. First I would like to know if someone would have a suggestion for a regular expression that would replace all occurrence of each letter by its corresponding cipher letter (provided by user) at once and without overwriting anything. Example: In this case, user provides plaintext "TEST", and on his cipher alphabet, he wishes to have all his T's replaced with E's, E's replaced with Y and S replaced with J. My first thought was to substitute each occurrence of a letter with an individual character and then replace that character by the cipherletter corresponding to the plaintext letter provided. Using the same example word "TEST", the steps taken by the program to provide an answer would be: 1 - replace T's with (lets say) @ 2 - replace E's with # 3 - replace S's with & 4 - Replace @ with E, # with Y, & with j 5 - Output = EYJE This solution doesn't seem to work for large texts. I would like to know if anyone can think of a single regular expression that would allow me to replace each letter in a given text by its corresponding letter in a 26-letter cipher alphabet without the need of splitting the task in an intermediate step as I mentioned. If it helps visualize the process, this is a print screen of my GUI for the program: http://img43.imageshack.us/img43/2118/11618743.jpg

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  • operator new for array of class without default constructor......

    - by skydoor
    For a class without default constructor, operator new and placement new can be used to declare an array of such class. When I read the code in More Effective C++, I found the code as below(I modified some part)..... My question is, why [] after the operator new is needed? I test it without it, it still works. Can any body explain that? class A { public: int i; A(int i):i(i) {} }; int main() { void *rawMemory = operator new[] (10 * sizeof(A)); // Why [] needed here? A *p = static_cast<A*>(rawMemory); for(int i = 0 ; i < 10 ; i++ ) { new(&p[i])A(i); } for(int i = 0 ; i < 10 ; i++ ) { cout<<p[i].i<<endl; } for(int i = 0 ; i < 10 ; i++ ) { p[i].~A(); } return 0; }

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  • JSF 2.0: Validate equality of 2 InputSecret Fields (confirm password) without writing Code?

    - by yournamehere
    I'm developing a pure JavaEE6 application with JSF 2.0 and Glassfish. My JSF implementation is Primefaces (beside Mojarra provided by Glassfish). I want to verify if the values of 2 password fields in a JSF form are equal. With Seam, there is the neat component <s:validateEquality for="pw1"/>. I want do to the same without Seam, just using JSF (or maybe a component of a JSF library). Until now i only saw examples which validate the form with a custom validator. But i would like to compare the fields without writing Java code or Javascript code. Is that possible? This what it looks like with Seam: ... <h:inputSecret id="passwort" value="#{personHome.instance.password}" redisplay="true" required="true"> <f:validateLength minimum="8"/> <a:support event="onblur" reRender="passwortField" bypassUpdates="true" ajaxSingle="true" /> </h:inputSecret> ... <h:inputSecret id="passwort2" required="true" redisplay="true"> <!-- find the JSF2.0-equivalent to this tag: --> <s:validateEquality for="passwort"/> <a:support event="onblur" reRender="passwort2Field" bypassUpdates="true" ajaxSingle="true" /> </h:inputSecret> ... Any help is appreciated. Thanks!

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  • How should I write Jquery Mobile app for browsers with and without javascript support?

    - by Adrian Grigore
    Hi, I'm trying to wrap my head around jQuery Mobile. My aim is to build a very fast application with a look and feel as close as possible to a native app (at least for modern devices). I understand there are two ways of navigating between pages: Loading each page as a separate page and linking to other pages with regular html anchors. Putting all (or many) pages on one single web page and navigating between them by means of javascript ($.mobile.changePage (method) and similar api functions. The first approach should work on all browsers, but performs quite poorly since there is a delay between each page transition. The second looks like it should be much faster, so I would definitely prefer this approach. But how would that work for mobile device browsers without javascript support? It certainly seems to violate jQuery Mobile's aim to provide a gracefully degraded experience for C-grade browsers. It looks to me like I need to implement my app twice, once optimized for browsers with javascript support, once for browsers without? Using may be another option, but that looks even more messy. What's the recommended way to approach this dilemma? Is there anything I have not noticed? Thanks, Adrian

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  • WinForms - How do I access/call methods in UI thread from a separate thread without passing a delega

    - by Greg
    Hi, QUESTION: In .NET 3.5 WinForms apps, how do I access/call methods in UI thread from a separate thread, without passing a delegate? EXAMPLE: Say I have some code I want to run both (a) manually when the user clicks a button, and (b) periodically called by a process which is running in a separate non-mainUI thread but without passing a delegate. [Simplistically I'm thinking that the class that has this method is already been constructed, and the main UI thread has a handle to it, therefore if the process running in the separate thread could just get a handle to it from the main-UI thread it could call it. Hopefully this is not a flawed concept] BACKGROUND: I'm actually after a way to do the above for the case where my separate process thread is actually a job I schedule using quartz.net. The way the scheduler works I can't seem to actually pass in a delegate. There is a way to pass JobDetails, however it only seems to caters for things like string, int, etc. Hence what I'm after is a way to access the MainForm class for example, to call a method on it, from within the quartz.net job which runs in a separate thread. Thanks

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  • JDBC/OSGi and how to dynamically load drivers without explicitly stating dependencies in the bundle?

    - by Chris
    Hi, This is a biggie. I have a well-structured yet monolithic code base that has a primitive modular architecture (all modules implement interfaces yet share the same classpath). I realize the folly of this approach and the problems it represents when I go to deploy on application servers that may have different conflicting versions of my library. I'm dependent on around 30 jars right now and am mid-way though bnding them up. Now some of my modules are easy to declare the versioned dependencies of, such as my networking components. They statically reference classes within the JRE and other BNDded libraries but my JDBC related components instantiate via Class.forName(...) and can use one of any number of drivers. I am breaking everything up into OSGi bundles by service area. My core classes/interfaces. Reporting related components. Database access related components (via JDBC). etc.... I wish for my code to be able to still be used without OSGi via single jar file with all my dependencies and without OSGi at all (via JARJAR) and also to be modular via the OSGi meta-data and granular bundles with dependency information. How do I configure my bundle and my code so that it can dynamically utilize any driver on the classpath and/or within the OSGi container environment (Felix/Equinox/etc.)? Is there a run-time method to detect if I am running in an OSGi container that is compatible across containers (Felix/Equinox/etc.) ? Do I need to use a different class loading mechanism if I am in a OSGi container? Am I required to import OSGi classes into my project to be able to load an at-bundle-time-unknown JDBC driver via my database module? I also have a second method of obtaining a driver (via JNDI, which is only really applicable when running in an app server), do I need to change my JNDI access code for OSGi-aware app servers?

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  • Can I use manifests to consume a COM server without specifying its version?

    - by sharptooth
    Two of our programs use the same COM server (also made by us) with the same class ids. Each program when installing copies the COM server files into its folder and regsvr32s the COM server. The problem is how to install the COM server so that the user can install either one or both of our programs into different folders in any order and likely of different versions. Clearly it's impossible without changing the class ids and that's lots of hassle with configurations. Ideally we would like to use manifests for that and go without regsvr32. The problem is every time I read about reg-free COM (for example, here) there's the version attribute in the assemblyIdentity. The version number should change every nightly build and I totally don't like the idea of (automatically) adjusting it. I understand why specifying dependency on a specific version is good, but it's completely useless in our scenarion. Is there a way to write manifests for both the COM server and the consumer so that they don't specify versions and just work with whatever version of the file happens to be in the folder? Also is there a way to restrict the search to the same folder as the consumer?

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  • Is there a way to make changes to toggles in my .emacs file apply without re-starting Emacs?

    - by Vivi
    I want to be able to make the changes to my .emacs file without having to reload Emacs. I found three questions which sort of answer what I am asking (you can find them here, here and here), but the problem is that the change I have just made is to a toggle, and as the comments to two of the answers (a1, a2) to those questions explain, the solutions given there (such as M-x reload-file or M-x eval-buffer) don't apply to toggles. I imagine there is a way of toggling the variable again with a command, but if there is a way to reload the whole .emacs and have the all the toggles re-evaluated without having to specify them, I would prefer. In any case, I would also appreciate if someone told me how to toggle the value of a variable so that if I just changed one toggle I can do it with a command rather than re-start Emacs just for that (I am new to Emacs). I don't know how useful this information is, but the change I applied was the following (which I got from this answer to another question): (setq skeleton-pair t) (setq skeleton-pair-on-word t) (global-set-key (kbd "[") 'skeleton-pair-insert-maybe) (global-set-key (kbd "(") 'skeleton-pair-insert-maybe) (global-set-key (kbd "{") 'skeleton-pair-insert-maybe) (global-set-key (kbd "<") 'skeleton-pair-insert-maybe) Edit: I included the above in .emacs and reloaded Emacs, so that the changes took effect. Then I commented all of it out and tried M-x load-file. This doesn't work. The suggestion below (C-x C-e by PP works if I am using it to evaluate the toggle first time, but not when I want to undo it). I would like something that would evaluate the commenting out, if such thing exists... Thanks :)

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  • How to create extensible dynamic array in Java without using pre-made classes?

    - by AndrejaKo
    Yeah, it's a homework question, so givemetehkodezplsthx! :) Anyway, here's what I need to do: I need to have a class which will have among its attributes array of objects of another class. The proper way to do this in my opinion would be to use something like LinkedList, Vector or similar. Unfortunately, last time I did that, I got fire and brimstone from my professor, because according to his belief I was using advanced stuff without understanding basics. Now next obvious solution would be to create array with fixed number of elements and add checks to get and set which will see if the array is full. If it is full, they'd create new bigger array, copy older array's data to the new array and return the new array to the caller. If it's mostly empty, they'd create new smaller array and move data from old array to new. To me this looks a bit stupid. For my homework, there probably won't be more that 3 elements in an array, but I'd like to make a scalable solution without manually calculating statistics about how often is array filled, what is the average number of new elements added, then using results of calculation to calculate number of elements in new array and so on. By the way, there is no need to remove elements from the middle of the array. Any tips?

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  • .NET Regex - Replace multiple characters at once without overwriting?

    - by Everaldo Aguiar
    I'm implementing a c# program that should automatize a Mono-alphabetic substitution cipher. The functionality i'm working on at the moment is the simplest one: The user will provide a plain text and a cipher alphabet, for example: Plain text(input): THIS IS A TEST Cipher alphabet: A - Y, H - Z, I - K, S - L, E - J, T - Q Cipher Text(output): QZKL KL QJLQ I thought of using regular expressions since I've been programming in perl for a while, but I'm encountering some problems on c#. First I would like to know if someone would have a suggestion for a regular expression that would replace all occurrence of each letter by its corresponding cipher letter (provided by user) at once and without overwriting anything. Example: In this case, user provides plaintext "TEST", and on his cipher alphabet, he wishes to have all his T's replaced with E's, E's replaced with Y and S replaced with J. My first thought was to substitute each occurrence of a letter with an individual character and then replace that character by the cipherletter corresponding to the plaintext letter provided. Using the same example word "TEST", the steps taken by the program to provide an answer would be: 1 - replace T's with (lets say) @ 2 - replace E's with # 3 - replace S's with & 4 - Replace @ with E, # with Y, & with j 5 - Output = EYJE This solution doesn't seem to work for large texts. I would like to know if anyone can think of a single regular expression that would allow me to replace each letter in a given text by its corresponding letter in a 26-letter cipher alphabet without the need of splitting the task in an intermediate step as I mentioned. If it helps visualize the process, this is a print screen of my GUI for the program:

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  • Can a lambda can be used to change a List's values in-place ( without creating a new list)?

    - by Saint Hill
    I am trying to determine the correct way of transforming all the values in a List using the new lambdas feature in the upcoming release of Java 8 without creating a **new** List. This pertains to times when a List is passed in by a caller and needs to have a function applied to change all the contents to a new value. For example, the way Collections.sort(list) changes a list in-place. What is the easiest way given this transforming function and this starting list: String function(String s){ return [some change made to value of s]; } List<String> list = Arrays.asList("Bob", "Steve", "Jim", "Arbby"); The usual way of applying a change to all the values in-place was this: for (int i = 0; i < list.size(); i++) { list.set(i, function( list.get(i) ); } Does lambdas and Java 8 offer: an easier and more expressive way? a way to do this without setting up all the scaffolding of the for(..) loop?

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  • How to change database connection without compiling, using JBoss Seam?

    - by MLB
    Hi there: I am developing a web site in Eclipse using JBoss Seam 1.2. My site uses a database (named ALregcli) hosted in a MySQL server. That database has only one table named trazasfallos. The server I am using is local (localhost). When I deploy the site in an "X HOST", the MySQL server it is not in the same computer... the server is in an "Y HOST", so, the connection will not be stablished to the database. I was changing the Context.xml, but it didn't work. The only way it worked was changing the host to connect to in the Context.xml and "recompiling" all the project. Then, it generates the new version of the compiled class trazasfallos.class, and this is the file I have to overwrite for connecting to a new database server. The point is that I want to make the change without "recompiling" anything... Maybe there is a way to make only a "text change" and it will work (maybe in a .xml file)... but I don't know how to do it!! The question is: how to change the connection to the database without recompiling anything in the site?? I am sorry about my English, I am from Cuba.

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  • How to avoid concurrent execution of a time-consuming task without blocking?

    - by Diego V
    I want to efficiently avoid concurrent execution of a time-consuming task in a heavily multi-threaded environment without making threads wait for a lock when another thread is already running the task. Instead, in that scenario, I want them to gracefully fail (i.e. skip its attempt to execute the task) as fast as possible. To illustrate the idea considerer this unsafe (has race condition!) code: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing running = true; try { runExpensiveTask(); } finally { running = false; } } I though about using a variation of Double-Checked Locking (consider that running is a primitive 32-bit field, hence atomic, it could work fine even for Java below 5 without the need of volatile). It could look like this: private static boolean running = false; public void launchExpensiveTask() { if (running) return; // Do nothing synchronized (ThisClass.class) { if (running) return; running = true; try { runExpensiveTask(); } finally { running = false; } } } Maybe I should also use a local copy of the field as well (not sure now, please tell me). But then I realized that anyway I will end with an inner synchronization block, that still could hold a thread with the right timing at monitor entrance until the original executor leaves the critical section (I know the odds usually are minimal but in this case we are thinking in several threads competing for this long-running resource). So, could you think in a better approach?

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  • Granting administrator privileges to an application launched at startup without UAC prompt?

    - by iKenndac
    Background I've written a small C#/.NET 4.0 application that syncs various settings from a game installed in Program Files to and from other copies of the same game on different machines (think Chrome bookmark sync, but for this game). The sync itself is a relatively simple affair, dealing with files stored inside the game's Program Files folder. On my machine, this works fine without having to elevate my application through UAC. Windows 7 makes the game use Program Files virtualisation and my application works fine with that. However, on a lot of tester's machines, I'm getting reports that the application either can't work with the files and in come cases can't even see the game's folder! Having the user right-click and "Run as Administrator" solves the problem in every case. So, we just set the application's manifest to require admin privileges, right? That's fine (although not ideal) for when the user manually invokes the application or the sync process because they'll be interacting with the application and ready to accept a UAC request. However, one of the features of my application is a "Sync Automatically" option, which allows the user to "set and forget" the application. With this set, the application puts itself into the registry at HKCU\Software\Microsoft\Windows\CurrentVersion\Run to be run at startup and sits in the system tray syncing the settings in the background as needed. Obviously, I need to be smarter here. Presenting a UAC prompt as soon as the user logs in to their account or at random intervals afterwards isn't the way forwards. So, my question! What's the best way to approach a situation where I'd need to run an application at startup that needs administrator privileges? Is there a way to have the user authorise an installation that causes the system to automatically run the application with the correct privileges without a prompt at startup/login?

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  • GTK+: How do I process RadioMenuItem choice without marking it chosen? And vise versa

    - by eugene.shatsky
    In my program, I've got a menu with a group of RadioMenuItem entries. Choosing one of them should trigger a function which can either succeed or fail. If it fails, this RadioMenuItem shouldn't be marked chosen (the previous one should persist). Besides, sometimes I want to set marked item without running the choice processing function. Here is my current code: # Update seat menu list def update_seat_menu(self, seats, selected_seat=None): seat_menu = self.builder.get_object('seat_menu') # Delete seat menu items for menu_item in seat_menu: # TODO: is it a good way? does remove() delete obsolete menu_item from memory? if menu_item.__class__.__name__ == 'RadioMenuItem': seat_menu.remove(menu_item) # Fill menu with new items group = [] for seat in seats: menu_item = Gtk.RadioMenuItem.new_with_label(group, str(seat[0])) group = menu_item.get_group() seat_menu.append(menu_item) if str(seat[0]) == selected_seat: menu_item.activate() menu_item.connect("activate", self.choose_seat, str(seat[0])) menu_item.show() # Process item choice def choose_seat(self, entry, seat_name): # Looks like this is called when item is deselected, too; must check if active if entry.get_active(): # This can either succeed or fail self.logind.AttachDevice(seat_name, '/sys'+self.device_syspath, True) Chosen RadioMenuItem gets marked irrespective of the choose_seat() execution result; and the only way to set marked item without triggering choose_seat() is to re-run update_seat_menu() with selected_seat argument, which is an overkill. I tried to connect choose_seat() with 'button-release-event' instead of 'activate' and call entry.activate() in choose_seat() if AttachDevice() succeeds, but this resulted in whole X desktop lockup until AttachDevice() timed out, and chosen item still got marked.

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  • How does Haskell do pattern matching without us defining an Eq on our data types?

    - by devoured elysium
    I have defined a binary tree: data Tree = Null | Node Tree Int Tree and have implemented a function that'll yield the sum of the values of all its nodes: sumOfValues :: Tree -> Int sumOfValues Null = 0 sumOfValues (Node Null v Null) = v sumOfValues (Node Null v t2) = v + (sumOfValues t2) sumOfValues (Node t1 v Null) = v + (sumOfValues t1) sumOfValues (Node t1 v t2) = v + (sumOfValues t1) + (sumOfValues t2) It works as expected. I had the idea of also trying to implement it using guards: sumOfValues2 :: Tree -> Int sumOfValues2 Null = 0 sumOfValues2 (Node t1 v t2) | t1 == Null && t2 == Null = v | t1 == Null = v + (sumOfValues2 t2) | t2 == Null = v + (sumOfValues2 t1) | otherwise = v + (sumOfValues2 t1) + (sumOfValues2 t2) but this one doesn't work because I haven't implemented Eq, I believe: No instance for (Eq Tree) arising from a use of `==' at zzz3.hs:13:3-12 Possible fix: add an instance declaration for (Eq Tree) In the first argument of `(&&)', namely `t1 == Null' In the expression: t1 == Null && t2 == Null In a stmt of a pattern guard for the definition of `sumOfValues2': t1 == Null && t2 == Null The question that has to be made, then, is how can Haskell make pattern matching without knowing when a passed argument matches, without resorting to Eq?

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  • New features of C# 4.0

    This article covers New features of C# 4.0. Article has been divided into below sections. Introduction. Dynamic Lookup. Named and Optional Arguments. Features for COM interop. Variance. Relationship with Visual Basic. Resources. Other interested readings… 22 New Features of Visual Studio 2008 for .NET Professionals 50 New Features of SQL Server 2008 IIS 7.0 New features Introduction It is now close to a year since Microsoft Visual C# 3.0 shipped as part of Visual Studio 2008. In the VS Managed Languages team we are hard at work on creating the next version of the language (with the unsurprising working title of C# 4.0), and this document is a first public description of the planned language features as we currently see them. Please be advised that all this is in early stages of production and is subject to change. Part of the reason for sharing our plans in public so early is precisely to get the kind of feedback that will cause us to improve the final product before it rolls out. Simultaneously with the publication of this whitepaper, a first public CTP (community technology preview) of Visual Studio 2010 is going out as a Virtual PC image for everyone to try. Please use it to play and experiment with the features, and let us know of any thoughts you have. We ask for your understanding and patience working with very early bits, where especially new or newly implemented features do not have the quality or stability of a final product. The aim of the CTP is not to give you a productive work environment but to give you the best possible impression of what we are working on for the next release. The CTP contains a number of walkthroughs, some of which highlight the new language features of C# 4.0. Those are excellent for getting a hands-on guided tour through the details of some common scenarios for the features. You may consider this whitepaper a companion document to these walkthroughs, complementing them with a focus on the overall language features and how they work, as opposed to the specifics of the concrete scenarios. C# 4.0 The major theme for C# 4.0 is dynamic programming. Increasingly, objects are “dynamic” in the sense that their structure and behavior is not captured by a static type, or at least not one that the compiler knows about when compiling your program. Some examples include a. objects from dynamic programming languages, such as Python or Ruby b. COM objects accessed through IDispatch c. ordinary .NET types accessed through reflection d. objects with changing structure, such as HTML DOM objects While C# remains a statically typed language, we aim to vastly improve the interaction with such objects. A secondary theme is co-evolution with Visual Basic. Going forward we will aim to maintain the individual character of each language, but at the same time important new features should be introduced in both languages at the same time. They should be differentiated more by style and feel than by feature set. The new features in C# 4.0 fall into four groups: Dynamic lookup Dynamic lookup allows you to write method, operator and indexer calls, property and field accesses, and even object invocations which bypass the C# static type checking and instead gets resolved at runtime. Named and optional parameters Parameters in C# can now be specified as optional by providing a default value for them in a member declaration. When the member is invoked, optional arguments can be omitted. Furthermore, any argument can be passed by parameter name instead of position. COM specific interop features Dynamic lookup as well as named and optional parameters both help making programming against COM less painful than today. On top of that, however, we are adding a number of other small features that further improve the interop experience. Variance It used to be that an IEnumerable<string> wasn’t an IEnumerable<object>. Now it is – C# embraces type safe “co-and contravariance” and common BCL types are updated to take advantage of that. Dynamic Lookup Dynamic lookup allows you a unified approach to invoking things dynamically. With dynamic lookup, when you have an object in your hand you do not need to worry about whether it comes from COM, IronPython, the HTML DOM or reflection; you just apply operations to it and leave it to the runtime to figure out what exactly those operations mean for that particular object. This affords you enormous flexibility, and can greatly simplify your code, but it does come with a significant drawback: Static typing is not maintained for these operations. A dynamic object is assumed at compile time to support any operation, and only at runtime will you get an error if it wasn’t so. Oftentimes this will be no loss, because the object wouldn’t have a static type anyway, in other cases it is a tradeoff between brevity and safety. In order to facilitate this tradeoff, it is a design goal of C# to allow you to opt in or opt out of dynamic behavior on every single call. The dynamic type C# 4.0 introduces a new static type called dynamic. When you have an object of type dynamic you can “do things to it” that are resolved only at runtime: dynamic d = GetDynamicObject(…); d.M(7); The C# compiler allows you to call a method with any name and any arguments on d because it is of type dynamic. At runtime the actual object that d refers to will be examined to determine what it means to “call M with an int” on it. The type dynamic can be thought of as a special version of the type object, which signals that the object can be used dynamically. It is easy to opt in or out of dynamic behavior: any object can be implicitly converted to dynamic, “suspending belief” until runtime. Conversely, there is an “assignment conversion” from dynamic to any other type, which allows implicit conversion in assignment-like constructs: dynamic d = 7; // implicit conversion int i = d; // assignment conversion Dynamic operations Not only method calls, but also field and property accesses, indexer and operator calls and even delegate invocations can be dispatched dynamically: dynamic d = GetDynamicObject(…); d.M(7); // calling methods d.f = d.P; // getting and settings fields and properties d[“one”] = d[“two”]; // getting and setting thorugh indexers int i = d + 3; // calling operators string s = d(5,7); // invoking as a delegate The role of the C# compiler here is simply to package up the necessary information about “what is being done to d”, so that the runtime can pick it up and determine what the exact meaning of it is given an actual object d. Think of it as deferring part of the compiler’s job to runtime. The result of any dynamic operation is itself of type dynamic. Runtime lookup At runtime a dynamic operation is dispatched according to the nature of its target object d: COM objects If d is a COM object, the operation is dispatched dynamically through COM IDispatch. This allows calling to COM types that don’t have a Primary Interop Assembly (PIA), and relying on COM features that don’t have a counterpart in C#, such as indexed properties and default properties. Dynamic objects If d implements the interface IDynamicObject d itself is asked to perform the operation. Thus by implementing IDynamicObject a type can completely redefine the meaning of dynamic operations. This is used intensively by dynamic languages such as IronPython and IronRuby to implement their own dynamic object models. It will also be used by APIs, e.g. by the HTML DOM to allow direct access to the object’s properties using property syntax. Plain objects Otherwise d is a standard .NET object, and the operation will be dispatched using reflection on its type and a C# “runtime binder” which implements C#’s lookup and overload resolution semantics at runtime. This is essentially a part of the C# compiler running as a runtime component to “finish the work” on dynamic operations that was deferred by the static compiler. Example Assume the following code: dynamic d1 = new Foo(); dynamic d2 = new Bar(); string s; d1.M(s, d2, 3, null); Because the receiver of the call to M is dynamic, the C# compiler does not try to resolve the meaning of the call. Instead it stashes away information for the runtime about the call. This information (often referred to as the “payload”) is essentially equivalent to: “Perform an instance method call of M with the following arguments: 1. a string 2. a dynamic 3. a literal int 3 4. a literal object null” At runtime, assume that the actual type Foo of d1 is not a COM type and does not implement IDynamicObject. In this case the C# runtime binder picks up to finish the overload resolution job based on runtime type information, proceeding as follows: 1. Reflection is used to obtain the actual runtime types of the two objects, d1 and d2, that did not have a static type (or rather had the static type dynamic). The result is Foo for d1 and Bar for d2. 2. Method lookup and overload resolution is performed on the type Foo with the call M(string,Bar,3,null) using ordinary C# semantics. 3. If the method is found it is invoked; otherwise a runtime exception is thrown. Overload resolution with dynamic arguments Even if the receiver of a method call is of a static type, overload resolution can still happen at runtime. This can happen if one or more of the arguments have the type dynamic: Foo foo = new Foo(); dynamic d = new Bar(); var result = foo.M(d); The C# runtime binder will choose between the statically known overloads of M on Foo, based on the runtime type of d, namely Bar. The result is again of type dynamic. The Dynamic Language Runtime An important component in the underlying implementation of dynamic lookup is the Dynamic Language Runtime (DLR), which is a new API in .NET 4.0. The DLR provides most of the infrastructure behind not only C# dynamic lookup but also the implementation of several dynamic programming languages on .NET, such as IronPython and IronRuby. Through this common infrastructure a high degree of interoperability is ensured, but just as importantly the DLR provides excellent caching mechanisms which serve to greatly enhance the efficiency of runtime dispatch. To the user of dynamic lookup in C#, the DLR is invisible except for the improved efficiency. However, if you want to implement your own dynamically dispatched objects, the IDynamicObject interface allows you to interoperate with the DLR and plug in your own behavior. This is a rather advanced task, which requires you to understand a good deal more about the inner workings of the DLR. For API writers, however, it can definitely be worth the trouble in order to vastly improve the usability of e.g. a library representing an inherently dynamic domain. Open issues There are a few limitations and things that might work differently than you would expect. · The DLR allows objects to be created from objects that represent classes. However, the current implementation of C# doesn’t have syntax to support this. · Dynamic lookup will not be able to find extension methods. Whether extension methods apply or not depends on the static context of the call (i.e. which using clauses occur), and this context information is not currently kept as part of the payload. · Anonymous functions (i.e. lambda expressions) cannot appear as arguments to a dynamic method call. The compiler cannot bind (i.e. “understand”) an anonymous function without knowing what type it is converted to. One consequence of these limitations is that you cannot easily use LINQ queries over dynamic objects: dynamic collection = …; var result = collection.Select(e => e + 5); If the Select method is an extension method, dynamic lookup will not find it. Even if it is an instance method, the above does not compile, because a lambda expression cannot be passed as an argument to a dynamic operation. There are no plans to address these limitations in C# 4.0. Named and Optional Arguments Named and optional parameters are really two distinct features, but are often useful together. Optional parameters allow you to omit arguments to member invocations, whereas named arguments is a way to provide an argument using the name of the corresponding parameter instead of relying on its position in the parameter list. Some APIs, most notably COM interfaces such as the Office automation APIs, are written specifically with named and optional parameters in mind. Up until now it has been very painful to call into these APIs from C#, with sometimes as many as thirty arguments having to be explicitly passed, most of which have reasonable default values and could be omitted. Even in APIs for .NET however you sometimes find yourself compelled to write many overloads of a method with different combinations of parameters, in order to provide maximum usability to the callers. Optional parameters are a useful alternative for these situations. Optional parameters A parameter is declared optional simply by providing a default value for it: public void M(int x, int y = 5, int z = 7); Here y and z are optional parameters and can be omitted in calls: M(1, 2, 3); // ordinary call of M M(1, 2); // omitting z – equivalent to M(1, 2, 7) M(1); // omitting both y and z – equivalent to M(1, 5, 7) Named and optional arguments C# 4.0 does not permit you to omit arguments between commas as in M(1,,3). This could lead to highly unreadable comma-counting code. Instead any argument can be passed by name. Thus if you want to omit only y from a call of M you can write: M(1, z: 3); // passing z by name or M(x: 1, z: 3); // passing both x and z by name or even M(z: 3, x: 1); // reversing the order of arguments All forms are equivalent, except that arguments are always evaluated in the order they appear, so in the last example the 3 is evaluated before the 1. Optional and named arguments can be used not only with methods but also with indexers and constructors. Overload resolution Named and optional arguments affect overload resolution, but the changes are relatively simple: A signature is applicable if all its parameters are either optional or have exactly one corresponding argument (by name or position) in the call which is convertible to the parameter type. Betterness rules on conversions are only applied for arguments that are explicitly given – omitted optional arguments are ignored for betterness purposes. If two signatures are equally good, one that does not omit optional parameters is preferred. M(string s, int i = 1); M(object o); M(int i, string s = “Hello”); M(int i); M(5); Given these overloads, we can see the working of the rules above. M(string,int) is not applicable because 5 doesn’t convert to string. M(int,string) is applicable because its second parameter is optional, and so, obviously are M(object) and M(int). M(int,string) and M(int) are both better than M(object) because the conversion from 5 to int is better than the conversion from 5 to object. Finally M(int) is better than M(int,string) because no optional arguments are omitted. Thus the method that gets called is M(int). Features for COM interop Dynamic lookup as well as named and optional parameters greatly improve the experience of interoperating with COM APIs such as the Office Automation APIs. In order to remove even more of the speed bumps, a couple of small COM-specific features are also added to C# 4.0. Dynamic import Many COM methods accept and return variant types, which are represented in the PIAs as object. In the vast majority of cases, a programmer calling these methods already knows the static type of a returned object from context, but explicitly has to perform a cast on the returned value to make use of that knowledge. These casts are so common that they constitute a major nuisance. In order to facilitate a smoother experience, you can now choose to import these COM APIs in such a way that variants are instead represented using the type dynamic. In other words, from your point of view, COM signatures now have occurrences of dynamic instead of object in them. This means that you can easily access members directly off a returned object, or you can assign it to a strongly typed local variable without having to cast. To illustrate, you can now say excel.Cells[1, 1].Value = "Hello"; instead of ((Excel.Range)excel.Cells[1, 1]).Value2 = "Hello"; and Excel.Range range = excel.Cells[1, 1]; instead of Excel.Range range = (Excel.Range)excel.Cells[1, 1]; Compiling without PIAs Primary Interop Assemblies are large .NET assemblies generated from COM interfaces to facilitate strongly typed interoperability. They provide great support at design time, where your experience of the interop is as good as if the types where really defined in .NET. However, at runtime these large assemblies can easily bloat your program, and also cause versioning issues because they are distributed independently of your application. The no-PIA feature allows you to continue to use PIAs at design time without having them around at runtime. Instead, the C# compiler will bake the small part of the PIA that a program actually uses directly into its assembly. At runtime the PIA does not have to be loaded. Omitting ref Because of a different programming model, many COM APIs contain a lot of reference parameters. Contrary to refs in C#, these are typically not meant to mutate a passed-in argument for the subsequent benefit of the caller, but are simply another way of passing value parameters. It therefore seems unreasonable that a C# programmer should have to create temporary variables for all such ref parameters and pass these by reference. Instead, specifically for COM methods, the C# compiler will allow you to pass arguments by value to such a method, and will automatically generate temporary variables to hold the passed-in values, subsequently discarding these when the call returns. In this way the caller sees value semantics, and will not experience any side effects, but the called method still gets a reference. Open issues A few COM interface features still are not surfaced in C#. Most notably these include indexed properties and default properties. As mentioned above these will be respected if you access COM dynamically, but statically typed C# code will still not recognize them. There are currently no plans to address these remaining speed bumps in C# 4.0. Variance An aspect of generics that often comes across as surprising is that the following is illegal: IList<string> strings = new List<string>(); IList<object> objects = strings; The second assignment is disallowed because strings does not have the same element type as objects. There is a perfectly good reason for this. If it were allowed you could write: objects[0] = 5; string s = strings[0]; Allowing an int to be inserted into a list of strings and subsequently extracted as a string. This would be a breach of type safety. However, there are certain interfaces where the above cannot occur, notably where there is no way to insert an object into the collection. Such an interface is IEnumerable<T>. If instead you say: IEnumerable<object> objects = strings; There is no way we can put the wrong kind of thing into strings through objects, because objects doesn’t have a method that takes an element in. Variance is about allowing assignments such as this in cases where it is safe. The result is that a lot of situations that were previously surprising now just work. Covariance In .NET 4.0 the IEnumerable<T> interface will be declared in the following way: public interface IEnumerable<out T> : IEnumerable { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> : IEnumerator { bool MoveNext(); T Current { get; } } The “out” in these declarations signifies that the T can only occur in output position in the interface – the compiler will complain otherwise. In return for this restriction, the interface becomes “covariant” in T, which means that an IEnumerable<A> is considered an IEnumerable<B> if A has a reference conversion to B. As a result, any sequence of strings is also e.g. a sequence of objects. This is useful e.g. in many LINQ methods. Using the declarations above: var result = strings.Union(objects); // succeeds with an IEnumerable<object> This would previously have been disallowed, and you would have had to to some cumbersome wrapping to get the two sequences to have the same element type. Contravariance Type parameters can also have an “in” modifier, restricting them to occur only in input positions. An example is IComparer<T>: public interface IComparer<in T> { public int Compare(T left, T right); } The somewhat baffling result is that an IComparer<object> can in fact be considered an IComparer<string>! It makes sense when you think about it: If a comparer can compare any two objects, it can certainly also compare two strings. This property is referred to as contravariance. A generic type can have both in and out modifiers on its type parameters, as is the case with the Func<…> delegate types: public delegate TResult Func<in TArg, out TResult>(TArg arg); Obviously the argument only ever comes in, and the result only ever comes out. Therefore a Func<object,string> can in fact be used as a Func<string,object>. Limitations Variant type parameters can only be declared on interfaces and delegate types, due to a restriction in the CLR. Variance only applies when there is a reference conversion between the type arguments. For instance, an IEnumerable<int> is not an IEnumerable<object> because the conversion from int to object is a boxing conversion, not a reference conversion. Also please note that the CTP does not contain the new versions of the .NET types mentioned above. In order to experiment with variance you have to declare your own variant interfaces and delegate types. COM Example Here is a larger Office automation example that shows many of the new C# features in action. using System; using System.Diagnostics; using System.Linq; using Excel = Microsoft.Office.Interop.Excel; using Word = Microsoft.Office.Interop.Word; class Program { static void Main(string[] args) { var excel = new Excel.Application(); excel.Visible = true; excel.Workbooks.Add(); // optional arguments omitted excel.Cells[1, 1].Value = "Process Name"; // no casts; Value dynamically excel.Cells[1, 2].Value = "Memory Usage"; // accessed var processes = Process.GetProcesses() .OrderByDescending(p =&gt; p.WorkingSet) .Take(10); int i = 2; foreach (var p in processes) { excel.Cells[i, 1].Value = p.ProcessName; // no casts excel.Cells[i, 2].Value = p.WorkingSet; // no casts i++; } Excel.Range range = excel.Cells[1, 1]; // no casts Excel.Chart chart = excel.ActiveWorkbook.Charts. Add(After: excel.ActiveSheet); // named and optional arguments chart.ChartWizard( Source: range.CurrentRegion, Title: "Memory Usage in " + Environment.MachineName); //named+optional chart.ChartStyle = 45; chart.CopyPicture(Excel.XlPictureAppearance.xlScreen, Excel.XlCopyPictureFormat.xlBitmap, Excel.XlPictureAppearance.xlScreen); var word = new Word.Application(); word.Visible = true; word.Documents.Add(); // optional arguments word.Selection.Paste(); } } The code is much more terse and readable than the C# 3.0 counterpart. Note especially how the Value property is accessed dynamically. This is actually an indexed property, i.e. a property that takes an argument; something which C# does not understand. However the argument is optional. Since the access is dynamic, it goes through the runtime COM binder which knows to substitute the default value and call the indexed property. Thus, dynamic COM allows you to avoid accesses to the puzzling Value2 property of Excel ranges. Relationship with Visual Basic A number of the features introduced to C# 4.0 already exist or will be introduced in some form or other in Visual Basic: · Late binding in VB is similar in many ways to dynamic lookup in C#, and can be expected to make more use of the DLR in the future, leading to further parity with C#. · Named and optional arguments have been part of Visual Basic for a long time, and the C# version of the feature is explicitly engineered with maximal VB interoperability in mind. · NoPIA and variance are both being introduced to VB and C# at the same time. VB in turn is adding a number of features that have hitherto been a mainstay of C#. As a result future versions of C# and VB will have much better feature parity, for the benefit of everyone. Resources All available resources concerning C# 4.0 can be accessed through the C# Dev Center. Specifically, this white paper and other resources can be found at the Code Gallery site. Enjoy! span.fullpost {display:none;}

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  • Wrong number of args passed to: repl$repl

    - by grm
    Hi, I have a trouble with a compojure "Getting started" example that I do not seem to understand. When I run the example from http://weavejester.github.com/compojure/docs/getting-started.html ...I get the following error at the lein repl step: ~/hello-www> lein repl src/hello_www/core.clj Exception in thread "main" java.lang.IllegalArgumentException: Wrong number of args passed to: repl$repl (NO_SOURCE_FILE:0) at clojure.lang.Compiler.eval(Compiler.java:5359) at clojure.lang.Compiler.eval(Compiler.java:5311) at clojure.core$eval__4350.invoke(core.clj:2364) at clojure.main$eval_opt__6502.invoke(main.clj:228) at clojure.main$initialize__6506.invoke(main.clj:247) at clojure.main$script_opt__6526.invoke(main.clj:263) at clojure.main$main__6544.doInvoke(main.clj:347) at clojure.lang.RestFn.invoke(RestFn.java:483) at clojure.lang.Var.invoke(Var.java:381) at clojure.lang.AFn.applyToHelper(AFn.java:180) at clojure.lang.Var.applyTo(Var.java:482) at clojure.main.main(main.java:37) Caused by: java.lang.IllegalArgumentException: Wrong number of args passed to: repl$repl at clojure.lang.AFn.throwArity(AFn.java:439) at clojure.lang.AFn.invoke(AFn.java:43) at clojure.lang.Var.invoke(Var.java:369) at clojure.lang.AFn.applyToHelper(AFn.java:165) at clojure.lang.Var.applyTo(Var.java:482) at clojure.core$apply__3776.invoke(core.clj:535) at leiningen.core$_main__59$fn__61.invoke(core.clj:94) at leiningen.core$_main__59.doInvoke(core.clj:91) at clojure.lang.RestFn.applyTo(RestFn.java:138) at clojure.core$apply__3776.invoke(core.clj:535) at leiningen.core$_main__59.invoke(core.clj:97) at user$eval__67.invoke(NO_SOURCE_FILE:1) at clojure.lang.Compiler.eval(Compiler.java:5343) ... 11 more I have tried both the stable and the developer version of lein without any success. Any ideas on what I could look for next? I get the same result both on linux and cygwin. When I run it manually, it seems to work fine on linux: java -cp "lib/*" clojure.main src/hello_www/core.clj 2010-05-17 19:34:17.280::INFO: Logging to STDERR via org.mortbay.log.StdErrLog 2010-05-17 19:34:17.281::INFO: jetty-6.1.14 2010-05-17 19:34:17.382::INFO: Started [email protected]:8080

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  • how to access a type defined in one .ml file in another .ml file

    - by user339261
    Hi, I m very new to ocaml and i m facing the problem below, In a.ml a record type t is defined and is also defined transparently in a.mli, i.e. in d interface so that the type definition is available to all other files. a.ml also has a function, func, which returns a list of t. Now in another file, b.ml i m calling func, now obviously ocaml compiler wud nt be able to infer d type of objects stored in d list, for compiler its just a list. so in b.ml, i hav something like dis, let tlist = A.func in let vart = List.hd tlist in printf "%s\n" vart.name (name is a field in record t) Now here i get a compiler error sayin "Unbound record field label name" which makes sense as compiler can't infer d type of vart. my first question: how do I explicitly provide d type of vart as t here? i tried doing "let vart:A.t = " but got the same error. I also tried creating another function to fetch the first element of d list and mentioning return type as A.t, but then i got the "Unbound value A.t". I did this: let firstt = function [] - 0 | x :: _ - A.t x ;; The problem is compiler is unable to recognize A.t (a type) in b.ml but is able to recognize function A.func. If I remove A.t from the b.ml, i don'get any compiler errors. Please help, its urgent work. Thanks in advance! ~Tarun

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  • Unable to run .exe application using C# code

    - by bjh Hans
    I have an exe that i need to call from my C# Program with two arguments(PracticeId,ClaimId) for example Suppose if i have an application "test.exe" , whose functionality is to make claim acording to given two argument On cmd i would normally give the following command as: test.exe 1 2 and it works fine and performs its job of conversion. but what if i want to execute the same thing using my c# code. i am using the following sample code: Process compiler = new Process(); compiler.StartInfo.FileName = "test.exe" ; compiler.StartInfo.Arguments = "1 2" ; compiler.StartInfo.UseShellExecute = true; compiler.StartInfo.RedirectStandardOutput = true; compiler.Start(); when i try to invoke the test.exe using the above code , it fails to perform its operation of making claim txt file what is the issue in this i don' know pls help me regarding this whether the problem of threding or not i don't know. Can anyone tell me if i need to add anything more to the above code It would be great if somebody could provide some help on the above topic.

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