As elixir_sinari and alister pointed out, there are some improvements possible to your command line to get where you want.
Two of the three lines you show in post #1 are error msgs output to stderr. No piped filter will see those unless you redirect stderr.
The grep cmd is pointless. awk can do this.
If you want do stop after the first matched output, you could close the pipe.
Given your post #1 sample, my comments to elixir_sinari's suggestion combined with alister's might do the job:
It will suppress error msgs, print the ifDescr.2500 to the outputfile as desired, and then exit and close the pipe, (hopefully) causing the snmpwalk cmd to terminate. Pls check out and come back with results.
Hi folks,
Please advise which command/command line shall I run;
1) to display the command and its output on console
2) simultaneous to save the command and its output on a file
I tried tee command as follows;
$ ps aux | grep mysql | tee /path/to/output.txt
It displayed the... (7 Replies)
How can I grep exactly a string that has .,/ characters using grep?
Example: I want to grep ONLY string1 and not string1.more or string1.more.evenmore
#lsauth ALL|grep 'string1'
All output:
string1 <--- This is the only I want.
string1.more
string1.evenmore.
more.string1... (4 Replies)
Hi,
I have written a shell script which is a combination of 5 scripts into one.
We have a Record Claim indicator in the scpt ($rc) with which we can come to an conclusion if the script failed to load the data or if the data loaded successfully.
Can any one please help me as to how to... (16 Replies)
I'm working on a script to make backup of various folder located on various host using different OS.
I got a strange behaviour because the script donět process all lines of a configuration file, the script execute only one loop even the input file have 6 lines:
This is the script:
#!/bin/bash... (4 Replies)
This has been bothering me for 3 days.
$> hostname
cepsun64amd
And I just want "cepsun",
I would normally do h=`hostname`; ${h%%64*}
But I am looking for a one-liner just for my own knowledge, because if there is a way to do this, I should know it by now.
Anyway, so is this... (2 Replies)
I am running the export command within a view to use that value inside my build script. But while executing it it is saying "export command not found"
My code is as follows:
--------------------------
#!/bin/sh
user="test"
DIR="/bldtmp/"$user
VIEW="test.view1"
echo "TMPDIR before export... (4 Replies)
Hi All,
I have a file with name
Is there a LINUX command that will help me to output the word after the 9th Underscore(_).
ie the output should be DLY in this case.
Can anybody pls help me.
Thanks much in advance,
Freddie (4 Replies)
below is the output xml string from some other command and i will be parsing it using awk
cat /tmp/alerts.xml
<Alert id="10102" name="APP-DS-ds_ha-140018-componentFailure-S" alertDefinitionId="13982" resourceId="11427" ctime="1359453507621" fixed="false" reason="If Event/Log Level(ANY) and... (2 Replies)
I am using UNIX to create a script on our system. I have setup my commands to append their output to an outage file. However, some of the commands return no output and so I would like something to take their place.
What I need
The following command is placed at the prompt:
TICLI... (4 Replies)
Discussion started by: jbrass
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)