12-01-2011
set is built into bash, but it's also a POSIX feature expected of any shell, which is why there's two man pages.
9 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
What the folowing statements means and whats the use of it ?
expr $db_name + 2 >/dev/null 2>&1
Thanks. (7 Replies)
Discussion started by: dhananjaysk
7 Replies
2. UNIX for Dummies Questions & Answers
whats the purpose of the following script? who could run it? To what is the script refering that exceeds 75%? The mailbox?
What does sed 's/%//' do? (1 Reply)
Discussion started by: vrn
1 Replies
3. Shell Programming and Scripting
Hi all,
I am unable interpret this code .........
nohup $OPSSHLPATH/mkt_sas_load_cic.sh $db_name $process_id $loc_mm > $OPSLSTPATH/mkt_sas_load_cic.out &
Thanks ....In advance (7 Replies)
Discussion started by: dhananjaysk
7 Replies
4. Shell Programming and Scripting
Hi all,
#!/bin/ksh
BIN=/interface/Gunner
age=$1
directory="$2"
&& directory=.
cd "$directory" || exit 1
from=`$BIN/today -$age`
cd $BIN
for i in `cat filestoarchive.txt`;do
cd $i
find . -mtime 14 | grep -v '.tar$' | $BIN/dttmfilter | awk '$1<="'$from'"{ print;};' | \
done (2 Replies)
Discussion started by: kayarsenal
2 Replies
5. UNIX for Advanced & Expert Users
PATH="/clocal/mqbrkrs/user/mqsiadm/sanjay"
MAIL_RECIPIENTS="xyz@abc.com"
Subject="File accessed in last minutes:"
find $PATH -type f -amin -1 > temp.txt.$$
cat temp.txt.$$ | \
while read line
do
fuser -uV $line >> tempmail.txt
done
cat "$tempmail.txt" | mailx -s "$Subject"... (4 Replies)
Discussion started by: varungupta
4 Replies
6. UNIX for Dummies Questions & Answers
if
then
if
then
echo "fst argument is $1 "
else
if
then
"fst argument is $1"
fi
fi
fi
Can anyone tell me. My requirement is tht pass a string ..
Check whether it contains "-". If yes then check if it... (1 Reply)
Discussion started by: nehagupta2008
1 Replies
7. Shell Programming and Scripting
Hi all,
I have a shell script which uses "mailx -H" to get the subject of a email in a Linux system.
However, the subject is truncated, and I think it has something to do with the terminal width because it only returns the first 80 characters of each line.
I have tried "stty columns"... (7 Replies)
Discussion started by: mezzo
7 Replies
8. Shell Programming and Scripting
I'm a beginner in shell scripting (I'm using ksh). I'm manipulating some files and I'm using set -A to transform each read line into a numeric array.
However, inside the 'for' loop the options of set (ie '-A') are not recognized (the vi editor doesn't highlight it and it doesn't work).
Where... (4 Replies)
Discussion started by: kasumlolla
4 Replies
9. Shell Programming and Scripting
Hi,
I am looking for a shell script which serves the below purpose.
Please find below the algorithm for the same and any help on this would be highly appreciated.
1)set of strings need to be replaced among set of files(directory may contain different types of files)
2)It should search for... (10 Replies)
Discussion started by: Amulya
10 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)