I think function's in bash doesn't accept any variables.
Incorrect, they take parameters just fine.
You call them directly, outside [ ], like you would an external program.
And your function should use return to give an integer value that if can use in this manner. It's like exit but only quits a function or sourced script instead of the entire program. Zero means success, nonzero means failure, just like the exit status of an external utility. Your EC variable trick works but such indirectness isn't necessary.
Hi All,
I have a function which reads parameter and gets the value from config file.
The entry in the file can be either of two
Name=value or
Name=value
so if the variant is not present it should return me the generic value ie Name without variant.
I am first searching for variant in... (4 Replies)
Hi ,
I have three funcions f1, f2 and f3 .
f1 calls f2 and f2 calls f3 .
I have a global variable "period" which i want to pass to f3 .
Can i pass the variable directly in the definition of f3 ?
Pls help .
sars (4 Replies)
Hi,
I'm currently writing a bash script, that starts multiple threads:
____________________
#!/bin/bash
loop=0
while((loop!=10))
do
thread &
((loop++))
done
#wait for all sub-processes (thread) to finish
wait
___________________
Now I want to know, what happens, if a... (2 Replies)
Hi,
I have written a program in C and have to test the return value of the functions. So the normal way of doin this wud b
int rc
rc=myfunction(input);
if(rc=TRUE){
}
else{
}
But instead of doing this I have called the function in the if() condition. Does this have any... (2 Replies)
Executed the following if conditions .. and got different results .
only (( )) gave correct o/p with all scenarios .
Can anybody please let me know what is the difference between and ] and ((condition)) when used with if condition.
And why each condition gave different result.
1.... (2 Replies)
hi,
I have some problems in my simple script about the redirect echo stdout command inside a condition. Why is the echo command inside the elif still execute in the else command
Here are my simple script
After check on the two diff output the echo stdout redirect is present in two diff... (3 Replies)
HI
My doubt may be basic one but I need to get it clarified..
When i use "if" condition that checks for many AND, OR logical conditions
like
if ]; then
return 0
fi
Even the if condition fails it returns as zero.. Any clue..
But if i add else condition like
if ]; ... (2 Replies)
I have a script which does gunzip, zip and untar.
Input to the script is file name and file directory (where file is located)
I am reading the input parameters as follows:
FILENAME=$1
FILEDIR=$2
I have created 3 functions that are as follows:
1) gunzip file
2) unzip file... (2 Replies)
Dear All.
I have a script, which process files one by one. In the script I have two functions.
one sftp files to different server
the other from existing file create file with different name.
My question is:
Will sftp function recognize files names , which are created in another... (1 Reply)
Hi All,
Good Day, seeking for your assistance on how to not perform my 2nd, 3rd,4th etc.. function if my 1st function is in else condition.
#Body
function1()
{
if
then
echo "exist"
else
echo "not exist"
}
#if not exist in function1 my all other function will not proceed.... (4 Replies)
Discussion started by: meister29
4 Replies
LEARN ABOUT REDHAT
system
SYSTEM(3) Linux Programmer's Manual SYSTEM(3)NAME
system - execute a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *string);
DESCRIPTION
system() executes a command specified in string by calling /bin/sh -c string, 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 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 string 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
ANSI C, POSIX.2, BSD 4.3
NOTES
As mentioned, system() ignores SIGINT and SIGQUIT. This may make programs that call it from a loop uninterruptable, 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 suid or sgid 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 suid or sgid 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.)
The check for the availability of /bin/sh is not actually performed; it is always assumed to be available. ISO C specifies the check, but
POSIX.2 specifies that the return shall always be non-zero, since a system without the shell is not conforming, and it is this that is
implemented.
It is possible for the shell command to return 127, so that code is not a sure indication that the execve() call failed.
SEE ALSO sh(1), signal(2), wait(2), exec(3)
2001-09-23 SYSTEM(3)