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Using grep

Issue 18

From Issue #18
October 1995

Oct 01, 1995  By Eric Goebelbecker
 in
New Linux users unfamiliar with this standard Unix tool may not realize how useful it is. In this tutorial for the novice user, Eric demonstrates grep techniques.
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Some confuusion while searching using grep

Vinod Semwal's picture
Submitted by Vinod Semwal (not verified) on Thu, 06/10/2010 - 08:26.

I hav a dir and on that file present like this

-rw-r--r-- 1 vs users 1390254 Jun 2 01:00 abcdefg.1006010100.dat
-rw-r--r-- 1 vs users 1388800 Jun 3 01:00 abcdefg.1006020100.dat
-rw-r--r-- 1 vs users 1388555 Jun 4 01:00 abcdefg.1006030100.dat
-rw-r--r-- 1 vs users 1392184 Jun 5 01:00 abcdefg.1006040100.dat
-rw-r--r-- 1 vs users 1391747 Jun 6 01:00 abcdefg.1006050100.dat
-rw-r--r-- 1 vs users 1392099 Jun 7 01:00 abcdefg.1006060100.dat
-rw-r--r-- 1 vs users 1389362 Jun 8 01:00 abcdefg.1006070100.dat
-rw-r--r-- 1 vs users 1392676 Jun 9 01:00 abcdefg.1006080100.dat
-rw-r--r-- 1 vs users 1436696 Jun 10 01:00 abcdefg.1006090100.dat
-rw-r--r-- 1 vs users 1060539 Jun 10 18:39 abcdefg.1006100100.dat

please check output while i am using grep command in below manner ..

vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep abc*
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep "abc*"| tail
-rw-r--r-- 1 vs users 1390254 Jun 2 01:00 abcdefg.1006010100.dat
-rw-r--r-- 1 vs users 1388800 Jun 3 01:00 abcdefg.1006020100.dat
-rw-r--r-- 1 vs users 1388555 Jun 4 01:00 abcdefg.1006030100.dat
-rw-r--r-- 1 vs users 1392184 Jun 5 01:00 abcdefg.1006040100.dat
-rw-r--r-- 1 vs users 1391747 Jun 6 01:00 abcdefg.1006050100.dat
-rw-r--r-- 1 vs users 1392099 Jun 7 01:00 abcdefg.1006060100.dat
-rw-r--r-- 1 vs users 1389362 Jun 8 01:00 abcdefg.1006070100.dat
-rw-r--r-- 1 vs users 1392676 Jun 9 01:00 abcdefg.1006080100.dat
-rw-r--r-- 1 vs users 1436696 Jun 10 01:00 abcdefg.1006090100.dat
-rw-r--r-- 1 vs users 1059029 Jun 10 18:37 abcdefg.1006100100.dat
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep abc| tail
-rw-r--r-- 1 vs users 1390254 Jun 2 01:00 abcdefg.1006010100.dat
-rw-r--r-- 1 vs users 1388800 Jun 3 01:00 abcdefg.1006020100.dat
-rw-r--r-- 1 vs users 1388555 Jun 4 01:00 abcdefg.1006030100.dat
-rw-r--r-- 1 vs users 1392184 Jun 5 01:00 abcdefg.1006040100.dat
-rw-r--r-- 1 vs users 1391747 Jun 6 01:00 abcdefg.1006050100.dat
-rw-r--r-- 1 vs users 1392099 Jun 7 01:00 abcdefg.1006060100.dat
-rw-r--r-- 1 vs users 1389362 Jun 8 01:00 abcdefg.1006070100.dat
-rw-r--r-- 1 vs users 1392676 Jun 9 01:00 abcdefg.1006080100.dat
-rw-r--r-- 1 vs users 1436696 Jun 10 01:00 abcdefg.1006090100.dat
-rw-r--r-- 1 vs users 1060539 Jun 10 18:39 abcdefg.1006100100.dat
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep abc.*| tail -2
-rw-r--r-- 1 vs users 1436696 Jun 10 01:00 abcdefg.1006090100.dat
-rw-r--r-- 1 vs users 1060539 Jun 10 18:39 abcdefg.1006100100.dat
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep *abc| tail -2
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp > ls -ltr | grep *.abc| tail -2
vs@vodalksmvs2 /var/opt/nokia/smvs/tmp >

I want to know in what manner grep runs and giving output for above commands.

grep (-A|-B|-C)

Anonymous's picture
Submitted by Anonymous on Tue, 04/27/2010 - 13:12.

I use linux as my development environment. Grep with -A, -B and -C option provides me with context for what I'm searching. These options print out lines either above or below the target line.

For example I search for a function call and get grep to display the lines above and/or below the said line.

grep -p

iisdjp's picture
Submitted by iisdjp (not verified) on Wed, 11/18/2009 - 09:33.

I come from the AIX world. We have many scripts that use grep -p to get the paragraph containing a search string. I cannot find anything comparable to grep -p in Red Hat Linux. Any ideas?

grep -p

iisdjp's picture
Submitted by iisdjp (not verified) on Wed, 11/18/2009 - 11:42.

Never mind, I found this code. (Shoulda done more googling first! :-) )

#!/bin/sh

# usage: pargrep

inFile="$1"
searchString="$2"

awk '
BEGIN {
FS="\n"
RS=""
}
/'"$searchString"'/ { print }
' ${inFile}

non-standard args - could be made less confusing

Anonymous's picture
Submitted by Anonymous on Tue, 04/27/2010 - 09:24.

That's good as far as it goes, but you should reverse $1 and $2. NORMAL grep is:

grep

That pargrep is

grep

At least you should minimize the differences. Also, if you go with the "standard" way, a very small change to that script could be made to search across multiple files, just like grep would.

[sigh] stupid html. Ok, that

Anonymous's picture
Submitted by Anonymous on Tue, 04/27/2010 - 09:25.

[sigh] stupid html.

Ok, that should have read:

...
grep pattern filename

that pargrep is:

grep filename pattern
...

Question

Anonymous's picture
Submitted by Anonymous (not verified) on Sun, 09/27/2009 - 02:42.

Dear Sir,

How can i search in my lunix server for a word in the sources code for any file that is located in the vhost. for example:

I need to search for the word "iframe" in all the "vhosts" folder on my server. this word is in the "Sources code for all my files for my websites"

Can u help me in this please ?
i will too much greatfull for you
regards
samer

The fastest method is...

Anonymous's picture
Submitted by Anonymous on Tue, 04/27/2010 - 10:24.

The following, replacing "*.php" by your source files' extension:

$ find . -name "*.php" -print0 | xargs -0 grep iframe

Search

Mitch Frazier's picture
Submitted by Mitch Frazier on Sun, 09/27/2009 - 11:55.

There are a number of ways of doing that, try:

  $ find /path/to/vhosts -type f -exec grep --with-filename iframe {} \;

or try:

  $ grep -r iframe /path/to/vhosts/*

Mitch Frazier is an Associate Editor for Linux Journal.

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