Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Strange behavior of grep
Top Forums Shell Programming and Scripting Strange behavior of grep Post 302915430 by veeresh_15 on Wednesday 3rd of September 2014 04:24:15 AM
Old 09-03-2014
Oracle Strange behavior of grep
Hi All,

I am facing a strange problem while grepping for a process. Here is the small script that i have written.
It will look for any process running with the parameter passed to the script.
If no process is running it should print appropriate message.

Code:
[oracle@server]$ cat t.ksh
#!/bin/ksh

set -x

sid=$1
sid_cnt=$(ps -ef|grep -w "$sid"|grep -v "grep"|wc -l)
echo $sid_cnt
if [ $sid_cnt -eq 0 ];then
        echo "sid not runing"
        exit 1
else
        echo "sid running"
fi

I executed the script with a parameter "abc". There is no process running as "abc". But the output of the script shows otherwise
Code:
[oracle@server]$ ksh t.ksh abc
+ sid=abc
+ ps -ef
+ grep -w abc
+ grep -v grep
+ wc -l
+ sid_cnt=1
+ echo 1
1
+ [ 1 -eq 0 ]
+ echo 'sid running'
sid running

When i run below command on command prompt, i get a different(desired) output.

Code:
[oracle@server]$ sid=abc
[oracle@server]$ ps -ef|grep -w "$sid"|grep -v "grep"|wc -l
0


Can you please help why the command is behaving differently when run in a shell script & when run on a command line.

Regards,
Veeresham
 

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

strange sed behavior

I have a file called products.kp which contains, for example, 12345678,1^M 87654321,2^M 13579123,3 when I run the command cat products.kp| sed -f kp.sed where kp.sed contains s,^M,, I get the output 12345678,1 87654321,2 13579123,3 (5 Replies)
Discussion started by: Kevin Pryke
5 Replies

2. UNIX for Dummies Questions & Answers

Strange Behavior on COM2

Hi, I have a problem with a new touch screen controller that I am trying to use on a SCO 3.0 system. THe touch screen controller only wants to talk at 9600baud. I have updated /etc/inittab per the manual and also edited /usr/lib/event/devices to use 9600 baud. The only way I can get the... (0 Replies)
Discussion started by: Elwood51
0 Replies

3. Shell Programming and Scripting

Very Strange Behavior for redirection

I have searched far and wide for an explanation for some odd behavior for output redirection and haven't come up with anything. A co-worker was working on old scripts which have run for years and embedded in their code were output redirects which worked for the script during execution and then... (5 Replies)
Discussion started by: cahook
5 Replies

4. Shell Programming and Scripting

nawk strange behavior

Dear guys; when deleting repeated lines using nawk as below ; Why the below syntax works? nawk ' !a++' infile > outfile and when using the other below syntax the nawk doesn't work? nawk ' { !a++ } ' infile > outfile or nawk ' { !a++ } ' infile > outfile BR (4 Replies)
Discussion started by: ahmad.diab
4 Replies

5. Programming

Strange behavior in C++

I have the following program: int main(int argc, char** argv){ unsigned long int mean=0; for(int i=1;i<10;i++){ mean+=poisson(12); cout<<mean<<endl; } cout<<"Sum of poisson: "<< mean; return 0; } when I run it, I get the... (4 Replies)
Discussion started by: santiagorf
4 Replies

6. Ubuntu

Ubuntu strange behavior

It is so till login screen. I mean that when I boot my computer, Ubuntu shows a splash screen with mouse instead of Ubuntu logo and in the login screen it shows XUbuntu login screen... It began when I upgraded to previous kernel, I suppose, but I'm not sure... I can't say that it annoys me very... (6 Replies)
Discussion started by: Sapfeer
6 Replies

7. Red Hat

strange mail behavior

Hi I have script to to take backup and send mail to a group once a day. One strange behavior I have observed recently is that most of the time the mail we receive is fine . But someday it just sends out mail without any subject with undisclosed recipients. I dont know how to find the cause... (0 Replies)
Discussion started by: ningy
0 Replies

8. AIX

Strange behavior with tar

I am trying to create an archive using tar. I am specifying a list of directories using the -L option. For testing purposes I created a simple directory structure: /backup/test /backup/test/test1 /backup/test/test2 The file specified by the -L option, named files.txt, contains:... (8 Replies)
Discussion started by: judykstra
8 Replies

9. Shell Programming and Scripting

Strange Ctrl+C behavior

Hello All, I have a strange issue. I've created a shell script which connects to RMAN (Oracle Recovery Manager) and executes full DB backup. I then executed this script with nohup and in the background: $ nohup my_script.sh > logfile.log 2>&1 &The issue is that when I tried to take a look into... (6 Replies)
Discussion started by: JackK
6 Replies

LEARN ABOUT V7

zgrep

ZGREP(1)						      General Commands Manual							  ZGREP(1)

NAME

       zgrep - search possibly compressed files for a regular expression

SYNOPSIS

       zgrep [ grep_options ] [ -e ] pattern filename...

DESCRIPTION

       Zgrep  invokes  grep  on  compressed  or  gzipped  files.   These  grep	options  will  cause  zgrep  to  terminate  with  an  error  code:
       (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*).  All other options specified are passed directly to grep.  If no file is specified,  then  the
       standard input is decompressed if necessary and fed to grep.  Otherwise the given files are uncompressed if necessary and fed to grep.

       If the GREP environment variable is set, zgrep uses it as the grep program to be invoked.

EXIT CODE

       2 - An option that is not supported was specified.

AUTHOR

       Charles Levert (charles@comm.polymtl.ca)

SEE ALSO

       grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1)

																	  ZGREP(1)
All times are GMT -4. The time now is 06:32 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy