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  • copying a struct with a struct member to another struct

    - by user1839295
    is the following code correct? typedef struct { int x; int y; } OTHERSTRUCT; struct DATATYPE { char a; OTHERSTRUCT b; } // ... // now we reserve two structs struct DATATYPE structA; struct DATATYPE structB; // ... probably fill insome values // now we copy structA to structB structA = structB; Are both structs now completely identical? Even the "struct in the struct"? Thanks!

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  • struct to bidimensional struct pointer assigment in C

    - by argos.void
    i want to get work this code and i googled and asked in efnet and freenode but i didnt find the answer. what i want i to assign a struct woot to an another bidimensional struct woot *, and i need malloc to do that. then, how can i use malloc there and how to assign the struct? thanks. #include <stdio.h> struct omg { int foo; }; struct woot { struct omg *localfoo; int foo; }; int a = sizeof(struct woot); int main(void){ struct woot *what[10][10] = (struct woot *) malloc(100*a); struct omg hahaha[100]; hahaha[1].foo = 15; what[1][6].localfoo = &hahaha[1]; }

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  • c struct pointer issues

    - by clear2k
    I'm trying to cast a struct into another struct but I'm having incompatible pointer issues within the cast and the malloc under some_func (structs layout are the same) struct stu1 **some_func(struct stu1 *my_struct) { my_struct = (struct stu1 **)malloc(sizeof(struct stu1 *)*total_size); for(i=0;i<20;i++){ my_struct[i] = (struct stu1 *)malloc(sizeof(struct stu1)); printf("%s",my_struct[i++]->a); } } int main() { struct stu1 **my_struct; struct stu2 **my_struct2; struct stu3 **my_struct3; my_struct = some_func(my_struct); my_struct2 = (struct stu2**)some_func((struct stu1*)my_struct2); my_struct3 = (struct stu3**)some_func((struct stu1*)my_struct3); }

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  • Error in installing ZTE AC2738 on ubuntu 3.0.0-12-generic

    - by Netro
    I am getting this error ,struct usb_serial_driver has no member named shutdown. I am installing on 64bit ubuntu 3.0.0-12-generic ... Beginning Verify CD ... ... Verify CD Succeed! ... Beginning Copy Install Package Files ... ... will take a long time, waiting 5 seconds, please ... Copy Install Package Files Succeed! ... 'ztemtApp' previous version not found. and install now Beginning install ... ... Current linux release version is 'Ubuntu' ... Checking 'App' process ... Checking old installation ... Installing ... Current Path is : . : /tmp/ztemt_datacard/Linux 1. Checking Previous Version ... 2. Copying Data Bin ... ... will take a few seconds, please waiting ... /tmp/ztemt_datacard/Linux 3. Auto Load Usb Driver Module ... Rather than invoking init scripts through /etc/init.d, use the service(8) utility, e.g. service acpid restart Since the script you are attempting to invoke has been converted to an Upstart job, you may also use the stop(8) and then start(8) utilities, e.g. stop acpid ; start acpid. The restart(8) utility is also available. acpid stop/waiting acpid start/running, process 11802 4. Changing pppd Options ... 5. Changing File Permission ... 6. Deleting Qt lib When Local QT Vertion > V4.4.0 ... ... Package 'libqtgui4' exist ... QT_VERSION = 4 7. Deleting process id file: EVDOApp.pid ... 8. Making USB Serial Driver Module : ztemt.ko ... ... will take a few seconds, please waiting ... make -C /lib/modules/3.0.0-12-generic/build M=/usr/local/bin/ztemtApp/zteusbserial/below2.6.27 modules make[1]: Entering directory `/usr/src/linux-headers-3.0.0-12-generic' CC [M] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.o /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘destroy_serial’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:159:14: error: ‘struct usb_serial_driver’ has no member named ‘shutdown’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:165:18: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_open’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:241:36: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:246:8: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:251:6: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:253:10: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:265:3: warning: passing argument 1 of ‘serial->type->open’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:265:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:265:3: warning: passing argument 2 of ‘serial->type->open’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:265:3: note: expected ‘struct usb_serial_port *’ but argument is of type ‘struct file *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:270:20: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:276:6: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:278:6: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:279:20: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_close’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:355:18: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:357:10: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:358:21: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:371:8: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:372:10: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:375:3: error: too many arguments to function ‘port->serial->type->close’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:377:11: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:378:12: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:379:9: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:380:8: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:386:20: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_write’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:407:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: warning: passing argument 1 of ‘port->serial->type->write’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: warning: passing argument 2 of ‘port->serial->type->write’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: note: expected ‘struct usb_serial_port *’ but argument is of type ‘const unsigned char *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: warning: passing argument 3 of ‘port->serial->type->write’ makes pointer from integer without a cast [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: note: expected ‘const unsigned char *’ but argument is of type ‘int’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:413:2: error: too few arguments to function ‘port->serial->type->write’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_write_room’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:429:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:435:2: warning: passing argument 1 of ‘port->serial->type->write_room’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:435:2: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_chars_in_buffer’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:451:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:457:2: warning: passing argument 1 of ‘port->serial->type->chars_in_buffer’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:457:2: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_throttle’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:472:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:479:3: warning: passing argument 1 of ‘port->serial->type->throttle’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:479:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_unthrottle’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:491:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:498:3: warning: passing argument 1 of ‘port->serial->type->unthrottle’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:498:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_ioctl’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:511:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:518:3: warning: passing argument 1 of ‘port->serial->type->ioctl’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:518:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:518:3: warning: passing argument 2 of ‘port->serial->type->ioctl’ makes integer from pointer without a cast [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:518:3: note: expected ‘unsigned int’ but argument is of type ‘struct file *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:518:3: error: too many arguments to function ‘port->serial->type->ioctl’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_set_termios’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:535:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:542:3: warning: passing argument 1 of ‘port->serial->type->set_termios’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:542:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:542:3: warning: passing argument 2 of ‘port->serial->type->set_termios’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:542:3: note: expected ‘struct usb_serial_port *’ but argument is of type ‘struct termios *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:542:3: error: too few arguments to function ‘port->serial->type->set_termios’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_break’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:554:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:561:3: warning: passing argument 1 of ‘port->serial->type->break_ctl’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:561:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_tiocmget’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:629:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:635:3: warning: passing argument 1 of ‘port->serial->type->tiocmget’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:635:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:635:3: error: too many arguments to function ‘port->serial->type->tiocmget’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘serial_tiocmset’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:651:11: error: ‘struct usb_serial_port’ has no member named ‘open_count’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:657:3: warning: passing argument 1 of ‘port->serial->type->tiocmset’ from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:657:3: note: expected ‘struct tty_struct *’ but argument is of type ‘struct usb_serial_port *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:657:3: warning: passing argument 2 of ‘port->serial->type->tiocmset’ makes integer from pointer without a cast [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:657:3: note: expected ‘unsigned int’ but argument is of type ‘struct file *’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:657:3: error: too many arguments to function ‘port->serial->type->tiocmset’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘usb_serial_port_work’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:697:12: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘port_release’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:709:2: error: ‘struct device’ has no member named ‘bus_id’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘usb_serial_probe’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:858:2: error: implicit declaration of function ‘lock_kernel’ [-Werror=implicit-function-declaration] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:861:3: error: implicit declaration of function ‘unlock_kernel’ [-Werror=implicit-function-declaration] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1034:3: error: ‘struct usb_serial_port’ has no member named ‘mutex’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1182:23: error: ‘struct device’ has no member named ‘bus_id’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1182:51: error: ‘struct device’ has no member named ‘bus_id’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1183:3: error: ‘struct device’ has no member named ‘bus_id’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘usb_serial_disconnect’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1257:13: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1258:21: error: ‘struct usb_serial_port’ has no member named ‘tty’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: At top level: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1280:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1280:2: warning: (near initialization for ‘serial_ops.ioctl’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1281:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1281:2: warning: (near initialization for ‘serial_ops.set_termios’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1284:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1284:2: warning: (near initialization for ‘serial_ops.break_ctl’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1286:2: error: unknown field ‘read_proc’ specified in initializer /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1286:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1286:2: warning: (near initialization for ‘serial_ops.ioctl’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1287:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1287:2: warning: (near initialization for ‘serial_ops.tiocmget’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1288:2: warning: initialization from incompatible pointer type [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1288:2: warning: (near initialization for ‘serial_ops.tiocmset’) [enabled by default] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘usb_serial_init’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1352:2: error: implicit declaration of function ‘info’ [-Werror=implicit-function-declaration] /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c: In function ‘fixup_generic’: /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1406:2: error: ‘struct usb_serial_driver’ has no member named ‘shutdown’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1406:2: error: ‘struct usb_serial_driver’ has no member named ‘shutdown’ /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1406:1: error: ‘usb_serial_generic_shutdown’ undeclared (first use in this function) /usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.c:1406:1: note: each undeclared identifier is reported only once for each function it appears in cc1: some warnings being treated as errors make[2]: *** [/usr/local/bin/ztemtApp/zteusbserial/below2.6.27/usb-serial.o] Error 1 make[1]: *** [_module_/usr/local/bin/ztemtApp/zteusbserial/below2.6.27] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-3.0.0-12-generic' make: *** [modules] Error 2 Install finished! Any suggestion? Update: from installation document , In some special cases, the setup package can’t automatically compile the driver, so you need change the configurations yourself and manually compile the driver. Method: enter the directory: /usr/local/bin/ztemtApp/zteusbserial, and find the corresponding kernel version of current system. I can see 2.6.27 2.6.28 2.6.29 2.6.30 2.6.31 2.6.32 2.6.33 2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 below2.6.2 in the directory. Which version shall I pick up for installation? Readme file says, we have to do this to insert ztemt.ko in kernel.

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  • Union struct produces garbage and general question about struct nomenclature

    - by SoulBeaver
    I read about unions the other day( today ) and tried the sample functions that came with them. Easy enough, but the result was clear and utter garbage. The first example is: union Test { int Int; struct { char byte1; char byte2; char byte3; char byte4; } Bytes; }; where an int is assumed to have 32 bits. After I set a value Test t; t.Int = 7; and then cout cout << t.Bytes.byte1 << etc... the individual bytes, there is nothing displayed, but my computer beeps. Which is fairly odd I guess. The second example gave me even worse results. union SwitchEndian { unsigned short word; struct { unsigned char hi; unsigned char lo; } data; } Switcher; Looks a little wonky in my opinion. Anyway, from the description it says, this should automatically store the result in a high/little endian format when I set the value like Switcher.word = 7656; and calling with cout << Switcher.data.hi << endl The result of this were symbols not even defined in the ASCII chart. Not sure why those are showing up. Finally, I had an error when I tried correcting the example by, instead of placing Bytes at the end of the struct, positioning it right next to it. So instead of struct {} Bytes; I wanted to write struct Bytes {}; This tossed me a big ol' error. What's the difference between these? Since C++ cannot have unnamed structs it seemed, at the time, pretty obvious that the Bytes positioned at the beginning and at the end are the things that name it. Except no, that's not the entire answer I guess. What is it then?

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  • flexible length struct array inside another struct using C

    - by renz
    Hi I am trying to use C to implement a simple struct: 2 boxes, each contains different number of particles; the exact number of particles are passed in main(). I wrote the following code: typedef struct Particle{ float x; float y; float vx; float vy; }Particle; typedef struct Box{ Particle p[]; }Box; void make_box(Box *box, int number_of_particles); int main(){ Box b1, b2; make_box(&b1, 5); //create a box containing 5 particles make_box(&b2, 10); //create a box containing 10 particles } I've tried to implement make_box with the following code void make_box(struct Box *box, int no_of_particles){ Particle po[no_of_particles]; po[0].x = 1; po[1].x = 2; //so on and so forth... box->p = po; } It's always giving me "invalid use of flexible array member". Greatly appreciated if someone can shed some light on this.

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  • Core-audio - constructing an AudioBufferList struct (Q about c struct definition)

    - by mustISignUp
    The definition of AudioBufferList looks weird to me… i guess my C is not so good struct AudioBufferList { UInt32 mNumberBuffers; AudioBuffer mBuffers[kVariableLengthArray]; }; typedef struct AudioBufferList AudioBufferList; Why AudioBuffer mBuffers[kVariableLengthArray]; and not AudioBuffer *mBuffers; ? kVariableLengthArray appears to be == 1. Eh? I think i have it working but would appreciate it if anyone could set me straight.

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  • What makes this struct incomplete?

    - by Mechko
    gcc lovingly throws me this error: bst.c:33: error: invalid application of ‘sizeof’ to incomplete type ‘struct BSTNode’ What makes BSTnode incomplete? Below are the struct definitions relevant to BSTnode. struct BSTnode{ struct BSTnode * left; struct BSTnode * right; struct hash minhash; struct hash maxhash; struct DHTid owner; int misses; }; where we have: struct hash{ int hash; } struct DHTid { int islocal; unsigned long addr; unsigned short port; struct DHTnode * node; }; and currently: struct DHTnode{ int something; }

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  • Swig - wrapping C struct

    - by user289637
    Hello everyone, I am trying to write Python wrap for C code which uses struct. modules.c: struct foo { int a; }; struct foo bar; modulues.i %module nepal %{ struct foo { int a; } %} extern struct foo bar; But during compiling I am given error: In function ‘Swig_var_bar_set’: error: ‘bar’ undeclared (first use in this function) Could you be so kind to help me how to correctly define export struct variable ?

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  • Struct declaration error in C

    - by Spidfire
    ive got a struct problem it returns: cd.h:15: error: two or more data types in declaration specifiers its probably something simple ... struct cd { char titel[32]; char artiest[32]; int speelduur; }; typedef struct cd CD; struct cdlijst{ CD *item; struct cdlijst *next; } typedef struct cdlijst CDLijst;

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  • Useless variable name in C struct type definition

    - by user1210233
    I'm implementing a linked list in C. Here's a struct that I made, which represents the linked list: typedef struct llist { struct lnode* head; /* Head pointer either points to a node with data or NULL */ struct lnode* tail; /* Tail pointer either points to a node with data or NULL */ unsigned int size; /* Size of the linked list */ } list; Isn't the "llist" basically useless. When a client uses this library and makes a new linked list, he would have the following declaration: list myList; So typing llist just before the opening brace is practically useless, right? The following code basically does the same job: typedef struct { struct lnode* head; /* Head pointer either points to a node with data or NULL */ struct lnode* tail; /* Tail pointer either points to a node with data or NULL */ unsigned int size; /* Size of the linked list */ } list;

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  • Declaring struct in header file

    - by wrongusername
    I've been trying to include a structure called "student" in a student.h file, but I'm not quite sure how to do it. My student.h file code consists of entirely: #include<string> using namespace std; struct Student; while the student.cpp file consists of entirely: #include<string> using namespace std; struct Student { string lastName, firstName; //long list of other strings... just strings though }; Unfortunately, files that use #include "student.h" come up with numerous errors like error C2027: use of undefined type 'Student', error C2079: 'newStudent' uses undefined struct 'Student' (where newStudent is a function with a Student parameter), and error C2228: left of '.lastName' must have class/struct/union. It appears the compiler (VC++) does not recognize struct Student from "student.h" or something? I have tried declaring the whole struct in "student.h", but it didn't help either. How can I declare struct Student in "student.h" so that I can just #include "student.h" and start using the struct? BTW, it seems there are no compiler errors in student.h...

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  • Reading/Writing/Modifying a struct in C

    - by user1016401
    I am taking some information from a user (name, address, contact number) and store it in a struct. I then store this in a file which is opened in "r+" mode. I try reading it line by line and see if the entry I am trying to enter already exists, in which case I exit. Otherwise I append this entry at the end of the file. The problem is that when I open the file in "r+" mode, it gives me Segmentation fault! Here is the code: struct cust{ char *frstnam; char *lastnam; char *cntact; char *add; }; Now consider this function. I am passing a struct of information in this function. Its job is to check if this struct already exists else append it to end of file. void check(struct cust c) { struct cust cpy; FILE *f; f=fopen("Customer.txt","r+"); int num=0; if (f!= NULL){ while (!feof(f)) { num++; fread(&cpy,sizeof(struct cust),1,f); if ((cpy.frstnam==c.frstnam)&(cpy.lastnam==c.lastnam)&(cpy.cntact==c.cntact)&(cpy.add==c.add)) { printf("Hi %s %s. Nice to meet you again. You live at %s and your contact number is %s\n", cpy.frstnam,cpy.lastnam,cpy.add,cpy.cntact); return; } } fwrite(&c,sizeof(struct cust),1,f); fclose (f); } printf("number of lines read is %d\n",num); }

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  • can I access a struct inside of a struct without using the dot operator?

    - by yan bellavance
    I have 2 structures that have 90% of their fields the same. I want to group those fields in a structure but I do not want to use the dot operator to access them. The reason is I already coded with the first structure and have just created the second one. before: struct{ int a; int b; int c; object1 name; } str1; struct{ int a; int b; int c; object2 name; } str2; now I would create a third struct: struct{ int a; int b; int c; } str3; and would change the str1 and atr2 to this: struct{ str3 str; object1 name; } str1; struct { str3 str; object2 name; } str2; Finally I would like to be able to access a,b and c by doing: str1 myStruct; myStruct.a; myStruct.b; myStruct.c; and not: myStruct.str.a; myStruct.str.b; myStruct.str.c; Is there a way to do such a thing. The reason for doing this is I want keep the integrety of the data if chnges to the struct were to occur and to not repeat myself and not have to change my existing code and not have fields nested too deeply. RESOLVED: thx for all your answers. The final way of doing it so that I could use auto-completion also was the following: struct str11 { int a; int b; int c; }; typedef struct str22 : public str11 { QString name; }hi;

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  • C typedef struct uncertainty.

    - by Emanuel Ey
    Consider the following typedef struct in C: 21:typedef struct source{ 22: double ds; //ray step 23: double rx,zx; //source coords 24: double rbox1, rbox2; //the box that limits the range of the rays 25: double freqx; //source frequency 26: int64_t nThetas; //number of launching angles 27: double theta1, thetaN; //first and last launching angle 28:}source_t; I get the error: globals.h:21: error: redefinition of 'struct source' globals.h:28: error: conflicting types for 'source_t' globals.h:28: note: previous declaration of 'source_t' was here I've tried using other formats for this definition: struct source{ ... }; typedef struct source source_t; and typedef struct{ ... }source_t; Which both return the same error. Why does this happen? it looks perfectly right to me.

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  • how to allocate memory for struct itself, and its members

    - by Jack
    I have this struct: struct foo { char *a; char *b; char *c; char *d; }; it's possible allocate space for struct itself and its members instead of e.g, struct foo f; f.a = malloc(); f.b = malloc(); f.c = malloc(); f.d = malloc(); strcpy(f.a, "a"); strcpy(f.b, "b"); //.. something like this(of couse that it doesn't works): struct foo f = malloc(sizeof(struct f)); strpcy(f.a, "a"); //etc

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  • Write raw struct contents (bytes) to a file in C. Confused about actual size written

    - by d11wtq
    Basic question, but I expected this struct to occupy 13 bytes of space (1 for the char, 12 for the 3 unsigned ints). Instead, sizeof(ESPR_REL_HEADER) gives me 16 bytes. typedef struct { unsigned char version; unsigned int root_node_num; unsigned int node_size; unsigned int node_count; } ESPR_REL_HEADER; What I'm trying to do is initialize this struct with some values and write the data it contains (the raw bytes) to the start of a file, so that when I open this file I later I can reconstruct this struct and gain some meta data about what the rest of the file contains. I'm initializing the struct and writing it to the file like this: int esprime_write_btree_header(FILE * fp, unsigned int node_size) { ESPR_REL_HEADER header = { .version = 1, .root_node_num = 0, .node_size = node_size, .node_count = 1 }; return fwrite(&header, sizeof(ESPR_REL_HEADER), 1, fp); } Where node_size is currently 4 while I experiment. The file contains the following data after I write the struct to it: -bash$ hexdump test.dat 0000000 01 bf f9 8b 00 00 00 00 04 00 00 00 01 00 00 00 0000010 I expect it to actually contain: -bash$ hexdump test.dat 0000000 01 00 00 00 00 04 00 00 00 01 00 00 00 0000010 Excuse the newbiness. I am trying to learn :) How do I efficiently write just the data components of my struct to a file?

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  • C# struct with object as data member

    - by source-energy
    As we know, in C# structs are passed by value, not by reference. So if I have a struct with the following data members: private struct MessageBox { // data members private DateTime dm_DateTimeStamp; // a struct type private TimeSpan dm_TimeSpanInterval; // also a struct private ulong dm_MessageID; // System.Int64 type, struct private String dm_strMessage; // an object (hence a reference is stored here) // more methods, properties, etc ... } So when a MessageBox is passed as a parameter, a COPY is made on the stack, right? What does that mean in terms of how the data members are copied? The first two are struct types, so copies should be made of DateTime and TimeSpan. The third type is a primitive, so it's also copied. But what about the dm_strMessage, which is a reference to an object? When it's copied, another reference to the same String is created, right? The object itself resides in the heap, and is NOT copied (there is only one instance of it on the heap.) So now we have to references to the same object of type String. If the two references are accessed from different threads, it's conceivable that the String object could be corrupted by being modified from two different directions simultaneously. The MSDN documentation says that System.String is thread safe. Does that mean that the String class has a built-in mechanism to prevent an object being corrupted in exactly the type of situation described here? I'm trying to figure out if my MessageBox struct has any potential flaws / pitfalls being a structure vs. a class. Thanks for any input. Source.Energy.

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  • can I acces a struct inside of a struct without using the dot operator?

    - by yan bellavance
    I have 2 structures that have 90% of their fields the same. I want to group those fields in a structure but I do not want to use the dot operator to access them. The reason is I already coded with the first structure and have just created the second one. before: struct{ int a; int b; int c; object1 name; }str1; struct{ int a; int b; int c; object2 name; }str2; now I would create a third struct: struct{ int a; int b; int c; }str3; and would change the str1 and atr2 to this: struct{ str3 str; object1 name; }str1; struct { str3 str; object2 name; }str2; Finally I would like to be able to access a,b and c by doing: str1 myStruct; myStruct.a; myStruct.b; myStruct.c; and not: myStruct.str.a; myStruct.str.b; myStruct.str.c; Is there a way to do such a thing. The reason for doing this is I want keep the integrety of the data if chnges to the struct were to occur and to not repeat myself and not have to change my existing code and not have fields nested too deeply.

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  • Is the size of a struct required to be an exact multiple of the alignment of that struct?

    - by Steve314
    Once again, I'm questioning a longstanding belief. Until today, I believed that the alignment of the following struct would normally be 4 and the size would normally be 5... struct example { int m_Assume_32_Bits; char m_Assume_8_Bit_Bytes; }; Because of this assumption, I have data structure code that uses offsetof to determine the distance in bytes between two adjacent items in an array. Today, I spotted some old code that was using sizeof where it shouldn't, couldn't understand why I hadn't had bugs from it, coded up a unit test - and the test surprised me by passing. A bit of investigation showed that the sizeof the type I used for the test (similar to the struct above) was an exact multiple of the alignment - ie 8 bytes. It had padding after the final member. Here is an example of why I never expected this... struct example2 { example m_Example; char m_Why_Cant_This_Be_At_Offset_6_Bytes; }; A bit of Googling showed examples that make it clear that this padding after the final member is allowed - for example http://en.wikipedia.org/wiki/Data_structure_alignment#Data_structure_padding (the "or at the end of the structure" bit). This is a bit embarrassing, as I recently posted this comment - Use of struct padding (my first comment to that answer). What I can't seem to determine is whether this padding to an exact multiple of the alignment is guaranteed by the C++ standard, or whether it is just something that is permitted and that some (but maybe not all) compilers do. So - is the size of a struct required to be an exact multiple of the alignment of that struct according to the C++ standard? If the C standard makes different guarantees, I'm interested in that too, but the focus is on C++.

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  • C -- Basic Struct questions

    - by Ryan Yu
    So I'm trying to learn C right now, and I have some basic struct questions I'd like to clear up: Basically, everything centers around this snippet of code: #include <stdio.h> #include <stdlib.h> #define MAX_NAME_LEN 127 typedef struct { char name[MAX_NAME_LEN + 1]; unsigned long sid; } Student; /* return the name of student s */ const char* getName (const Student* s) { // the parameter 's' is a pointer to a Student struct return s->name; // returns the 'name' member of a Student struct } /* set the name of student s If name is too long, cut off characters after the maximum number of characters allowed. */ void setName(Student* s, const char* name) { // 's' is a pointer to a Student struct | 'name' is a pointer to the first element of a char array (repres. a string) s->name = name; } /* return the SID of student s */ unsigned long getStudentID(const Student* s) { // 's' is a pointer to a Student struct return s->sid; } /* set the SID of student s */ void setStudentID(Student* s, unsigned long sid) { // 's' is a pointer to a Student struct | 'sid' is a 'long' representing the desired SID s->sid = sid; } I've commented up the code in an attempt to solidify my understanding of pointers; I hope they're all accurate. So anyway, I have a feeling that setName and setStudentID aren't correct, but I'm not exactly sure why. Can someone explain? Thanks!

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  • Getting the name of a Clojure struct type?

    - by j-g-faustus
    When defining a struct type and instance, I can print the value and get the "struct" implementation type: (defstruct person :name :age) (def p (struct person "peter" 30)) user=> p {:name "peter", :age 30} user=> (type p) clojure.lang.PersistentStructMap But is it possible to tell whether p is an instance of the struct type "person"?

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  • Initializing a Global Struct in C

    - by Scott
    What is the best way to accomplish the following in C? #include <stdio.h> struct A { int x; }; struct A createA(int x) { struct A a; a.x = x; return a; } struct A a = createA(42); int main(int argc, char** argv) { printf("%d\n", a.x); return 0; } When I try to compile the above code, the compiler reports the following error: "initializer element is not constant" The bad line is this one: struct A a = createA(42); Can someone explain what is wrong? I'm not very experienced in C. Thanks!

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  • struct function

    - by gcc
    typedef struct phoneEntry { struct phoneEntry* next; char* info; char* number; } phoneEntry; typedef struct contactEntry { struct contactEntry* next; char* name; char* surname; struct phoneEntry* phoneList; } contactEntry; I want write a function that add a new contact to the phone book using given name and surname.(please, Note that a new contact should be located in the proper location which ensures the alphabetical ordering of the contacts.) void addContact(contactEntry** phoneBook, char* name, char* surname) { } I tried to write ,but ,unfortunetely, I cannot question is that there are any person who can help me.

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