I have two string returning function in ESQL/C
char *segment_name(lbuffer)
char *lbuffer;
{.....
and
char *get_bpdvalue(f_name)
char *f_name;
{......
both declared above main()
char *get_bpdvalue();
char *segment_name();
my problem is segment_name works on sprintf and strcpy... (5 Replies)
hi all,
my requirement is to create a thread by calling another function.
i.e i dont call pthread_create directly from main, but by calling another function (createThd - below ), from main.
Example:
void *thread_function(void *arg) { /* thread function */
int i;
rc =... (3 Replies)
hi
how can I return multiple values from a C function. I tried the following:
#include <stdio.h>
void foo(int id, char *first_name, char *last_name)
{
/*
this is just an example to illustrate my problem... real code makes
use of the "id" parameter.
*/
first_name = (char... (8 Replies)
Hello all,
I would like to know if it is possible to return a the result of a boolean expression from a function like this
function()
{
# some code
return ||
}
and what will be the return value ?
Thank you for help. (6 Replies)
Hi All
In my script, I can call on several functions. I have a logging function that is called by any of these functions. What I would like is some way of identifying which function I am using and pass this to the log function as some parameter.
Is there some built in command or way of... (3 Replies)
I am working on a C/Unix application from last 2 years which communicates with other systems using proprietary format of my client. We have a function written in C which returns integer, which is response from other system to the request message initiated by my system. This return value is then... (1 Reply)
I am working on the application in which I have to fetch values from the database and paste in url and send it to portal.
table=get_result("SELECT serialno,cas,Mode,FLC,TLC,location,CompName,CompCode,FG,FC,DispNo,TruckNo,LWbill,RRGPN,INVNO,DCN,RQTY,DQTY,SQTY,DDATE,RDATE,SDATE,TTIME FROM... (1 Reply)
H friends,
As we know, a function returns a value and that value is saved somwhere. like
int Sum( int x, int y )
{
return x + y;
}
Total = Sum( 10, 20 );
The value 30 is saved in variable Total.
Now the question is, what int value does the function main return, and where is it... (5 Replies)
Hi All,
I am using malloc function for allocating dynamic memory.
When I am using below code on Linux server its working fine, but When I am trying the same code on HP UNIX server its returning NULL.
below is a fragment of code in which it is giving problem.
tmp = (format_tree... (4 Replies)
Discussion started by: Taher Saifuddin
4 Replies
LEARN ABOUT CENTOS
system
SYSTEM(3) Linux Programmer's Manual SYSTEM(3)NAME
system - execute a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *command);
DESCRIPTION
system() executes a command specified in command by calling /bin/sh -c command, and returns after the command has been completed. During
execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT will be ignored.
RETURN VALUE
The value returned is -1 on error (e.g., fork(2) failed), and the return status of the command otherwise. This latter return status is in
the format specified in wait(2). Thus, the exit code of the command will be WEXITSTATUS(status). In case /bin/sh could not be executed,
the exit status will be that of a command that does exit(127).
If the value of command is NULL, system() returns nonzero if the shell is available, and zero if not.
system() does not affect the wait status of any other children.
CONFORMING TO
C89, C99, POSIX.1-2001.
NOTES
If the _XOPEN_SOURCE feature test macro is defined (before including any header files), then the macros described in wait(2) (WEXITSTA-
TUS(), etc.) are made available when including <stdlib.h>.
As mentioned, system() ignores SIGINT and SIGQUIT. This may make programs that call it from a loop uninterruptible, unless they take care
themselves to check the exit status of the child. E.g.
while (something) {
int ret = system("foo");
if (WIFSIGNALED(ret) &&
(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
break;
}
Do not use system() from a program with set-user-ID or set-group-ID privileges, because strange values for some environment variables might
be used to subvert system integrity. Use the exec(3) family of functions instead, but not execlp(3) or execvp(3). system() will not, in
fact, work properly from programs with set-user-ID or set-group-ID privileges on systems on which /bin/sh is bash version 2, since bash 2
drops privileges on startup. (Debian uses a modified bash which does not do this when invoked as sh.)
In versions of glibc before 2.1.3, the check for the availability of /bin/sh was not actually performed if command was NULL; instead it was
always assumed to be available, and system() always returned 1 in this case. Since glibc 2.1.3, this check is performed because, even
though POSIX.1-2001 requires a conforming implementation to provide a shell, that shell may not be available or executable if the calling
program has previously called chroot(2) (which is not specified by POSIX.1-2001).
It is possible for the shell command to return 127, so that code is not a sure indication that the execve(2) call failed.
SEE ALSO sh(1), signal(2), wait(2), exec(3)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2010-09-10 SYSTEM(3)