I need to find out if a variable contains a certain text string, then do something about it.
Here is what I mean, but I don't know how to get a "contains" operator
# We have volumes called:
# /Volumes/BackupsA_K
# /Volumes/BackupsL_Z
# /Volumes/Backups_Admin
# (could be more, etc)... (5 Replies)
When i tyr this, it gives me a syntax error...i tried removing quotes,removing spaces,replacing -eq with '='.. Can somebody suggest that is the problem?
if ]; then (4 Replies)
Hello everyone,
Just started UNIX today! In our school we use solaris. I just want to know how do I setup Solaris 10 not the GUI one, the one where you have to type the commands like ECHO, ls, pwd, etc... I have windows xp and I also have vmware.
I hope I am not missing anything! :p (4 Replies)
Hello everyone,
I am having to do a lot of perl scripting these days and I am learning a lot.
I have this problem
I want to move files from a folder and all its sub folders to one parent folder, they are all .gz files..
there is folder1\folder2\*.gz
and there are about 50 folders... (1 Reply)
Hi guys,
I confused about syntax used in OR script as follow:
I have this sample file separated by "|" containing:
January|Month No. 1
February|Month No. 2
March|Month No. 3
April|Month No. 4
May|Month No. 5
June|Month No. 6
July|Month No. 7
August|Month No. 8
September|Month No. 9... (11 Replies)
hi
i am writing a progrm to print the even numbers and the code which i am following is as follows
#!/usr/bin/bash
echo "enter a number a"
read a
if
then
echo "the number is even"
else
echo "the number is odd"
fi
~
what is the mistake i am doing ...please tell me (3 Replies)
Does anyone know how this line in bash works?
local gotbase= force= nicelevel corelimit
local pid base= user= nice= bg= pid_file=
local cgroup=
These lines are part of the daemon function inside the "functions" file at /etc/init.d in RH. (3 Replies)
Dear All,
I created a "new public repo" on GitHub (without the code for now but will post the code there as needed if anyone wants to fix a bug)
You can report any forum bugs and report issues in the GitHub "Issues Tab" for this repo here:
https://github.com/unixneo/unix.com.bugtracker
... (0 Replies)
Discussion started by: Neo
0 Replies
LEARN ABOUT LINUX
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 3.27 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)