grep is a command-line tool for searching text patterns in files

learn more… | top users | synonyms

4
votes
2answers
424 views

To grep 20 characters after and before match

I have the problem that I get too much information after the match for grep -RnisI --color=auto "pseudomonas" * I want to get only like 20 characters or 10 words after and before the match. What ...
4
votes
1answer
1k views

Why does grep sometimes show the file name, sometimes not?

Can somebody please explain to me why I don't get the full path in example 1? example 1 - returning found line grep MODIFY /opt/releases/packages/cr_c_cr6/sas/dbms/*/*; outcome: MODIFY example 2 ...
4
votes
3answers
1k views

shell script to read from multiple files in parallel

I need to write a script that runs parallel and looks for a string in multiple files. I tried a lot of options but they slow down the speed of my processor.
4
votes
1answer
113 views

command: ls /etc | sort | grep d* is yielding no results but ls /etc | sort | grep p* lists entire directory

I am playing around with piping and grep tonight. I know that grep uses regex and that * means 0 or more occurrences of the preceding character. So the way I understand it is that if I do the ...
4
votes
4answers
2k views

Grep for range of numbers [duplicate]

How would you search a log file for a date range? Log file looks like this: 01/14 00:00:01 INFO: received connect request from 10.10.10.10 I need to condense the log to 10 minutes starting ...
4
votes
1answer
594 views

Using Modifiers of Perl-compatible Regex (PCRE) in grep

According to grep --help and man grep, we can use the -P option in order to interpret the pattern as a Perl regular expression (PCRE, to be precise), instead of the default POSIX basic regular ...
4
votes
1answer
351 views

grep: display filename once, then display context with line numbers

Our source code has error codes scattered throughout. Finding them is easy with grep, but I'd like a bash function find_code that I can execute (eg. find_code ####) which will provide output along ...
4
votes
3answers
1k views

How can I grep for this or that (2 things) in a file?

I have a file that has "then"'s and "there"'s. I can $ grep "then " x.x x and then some x and then some x and then some x and then some and I can $ grep "there " x.x If there is no blob none ...
4
votes
2answers
568 views

how to use grep for specific files?

for example I type ls -altr | grep "23 Dec" so it will show files for 23 Dec only and I want to use grep for them, like ls -altr | grep "23 Dec" | xargs grep -l "some_string" but this doesn't ...
4
votes
1answer
2k views

What does \bi\b mean in a grep pattern?

What does this command do? grep "\bi\b" linux.txt What is it searching for?
4
votes
2answers
482 views

Why pidof and pgrep are behaving differently?

I have a init script in /etc/init.d/myservice for initialize a service like this: ... start() { ... daemon /usr/sbin/myservice ... } stop() { ... pgrep myservice pidof myservice ps -ef ...
4
votes
2answers
2k views

recursive search for a pattern, then for each match print out the specific SEQUENCE: line number, file name, and no file contents

What I am after is almost exactly the same as can be found here, but I want the format "line number, separator, filename, newline" in the results, thus displaying the line number at the beginning of ...
4
votes
1answer
768 views

How can I keep color codes with grep input?

It I grep something twice: ... | grep foo | grep bar It seems foo is not highlighted. Infact, it seems grep removes colorcodes from its input; Any way to prevent this?
4
votes
1answer
86 views

Printing Latex source with a2ps

When I try to print out latex source code with a2ps somefile.tex I get error messages from egrep like egrep: Das Ende des angegebenen Intervalls ist nicht gültig which translates to "the end of ...
4
votes
4answers
234 views

Grep of many keywords over many files: speeding it up

I am currently facing a "performance problem" while using grep. I am trying to locate the occurrences of many (10,000+) keywords in many (think Linux kernel repository size) files. The objective is to ...
4
votes
3answers
84 views

How to find files containing two strings in different lines

A real example is: I have a Python file util.py, and I changed one of the function name from foo to bar. There might be other files using foo as function name and they are irrelevant. I want to ...
4
votes
3answers
280 views

Search for specified keywords in files and copy to a new filename based on the keyword

I'm trying to create an .sh script where if any keyword is found in a file then copy that file to the directory /pathtofolder/keywords/$thefirstkeywordfound (overwrite the file if it already exists). ...
4
votes
2answers
1k views

greedy and lazy regular expressions (comprehension question)

I am teaching myself regular expressions, and I got stuck at »greedy« vs. »lazy« repeatings. What I found out so far is that »greedy« means that the RegExp ...
4
votes
4answers
423 views

Most efficient grep method

Currently I am grepping data from a file containing any of the following: ...
4
votes
1answer
4k views

Find and remove many files by specific content [duplicate]

Possible Duplicate: Arg list too long error while using find I try to find many files in many folders with specific content, and delete them. find dir.*/* -exec grep -l "content" {} \; | ...
4
votes
1answer
3k views

Delete last character in a word but only if the character is there - in bash

How to remove last character only if it's there? input: OpenOffice.org/m openOffice.org/ozm Pers. Pfg. phil. Prof. resp. Roonstr./m roonstr./ozm desired output: OpenOffice.org openOffice.org ...
4
votes
1answer
1k views

Bash, remove lines containing string with grep

This is currently deleting the whole contents of the file in question: #!/bin/bash rpc_port="9201"; dir="/etc/apache2/ports.conf" cat $dir | grep -v "Listen $rpc_port" > $dir The file contents: ...
4
votes
3answers
85 views

How do I combine the -v and -B switches in grep?

I have a list of currently installed kernels, and I'm trying to grep out both the currently installed kernel and the previously installed kernel. For this example, linux-image-3.2.0-60-generic is the ...
4
votes
1answer
69 views

Redirect grep out to a file does not work [closed]

I am doing a recursive grep by the following command: grep -r "load" . > tmp.txt However, when I hit enter, the command does not execute and bash is waiting for more inputs.. My OS is Ubuntu ...
4
votes
1answer
306 views

Grep multiple pattern negative match

So I have a bunch of Apache logs with using the standard log format. I want to get all the log lines that did not come from a web crawler. So lets say I have a file robot_patterns with entries like ...
4
votes
5answers
345 views

Multi-line grep beween two tags, only show the last match

I'm having a program that intermingles data segments into log output: log message log message ----BEGIN INLINE DATA---- data data data -----END INLINE DATA----- log messge I'm looking for something ...
4
votes
3answers
719 views

Delete the matching line and several more from a file

I have a text file called file_a.txt. My first command is grep -A 12 ".production =" file_a.txt The output is a few block. Each block of string contains 13 rows I specifically want to delete all ...
4
votes
1answer
33 views

grep variable-length optional text

I would like to search for edge-anchored text that has a block of preceding optional text, any amount of which can be included in the match. For instance, supposing I am trying to find ^xyz but would ...
4
votes
1answer
95 views

Blank lines when executing “grep | xargs” in a “find -exec”

I'm trying to list all directories of a web server that are blocked by Apache via a .htaccess (containing deny from all). I've managed to get the list of blocking .htaccess but when I try to extract ...
4
votes
3answers
855 views

Uniquely identifying java processes with same name

I have two java processes which run using the same file name, MyApp.jar (for example). /usr/java/latest/bin/java -jar MyApp.jar These jars exist in different places and use different ...
3
votes
5answers
380 views

Search among the content of a large number of plain text files?

I have a directory with 1,242,276 plain text files on my external hard drive. They are totally unorganized with meaningless numbers as their file names. The reason for that is because they were ...
3
votes
5answers
265 views

evaluate multiple patterns from program output and write into pattern specific files

I have a script outputting some value/numbers and I want to split those into two files. I am looking at something like: ./runme.sh | grep 'ook' >> ook.out | grep 'eek' >> eek.out Where ...
3
votes
5answers
293 views

How to get the lines that contain -R with grep

How can I find "-R" in files with grep? I tried grep "-R" *.GNU to get the lines that contain -R, but it returns nothing.
3
votes
5answers
2k views

Output multiple files from a single grep?

I'm not very experienced in shell scripting, but I'm trying to understand how to grep for a pattern and for each file where there is a match write a file to disk that contains the matched line from ...
3
votes
6answers
842 views

Remove lines that do not start with a pattern from a given set of patterns

I have a file that contains data like this: report aaaaaaaa - .. -th bbbbbbbbb -to ccccccccc .. --. Question: I want to remove any line that does not start with following strings : report ...
3
votes
6answers
153 views

ls content of a directory ignoring symlinks

I have a directory in which I would like to list all the content (files and sub directories) without showing the symbolic links. I am using GNU utilities on Linux. The ls version is 8.13. Example: ...
3
votes
2answers
519 views

Get 'less' to display filename

Something that seemed quite useful to me when looking for a certain var in a bunch of config files: less * | grep some_var So this returns the value of some_var without manually looking through all ...
3
votes
2answers
2k views

How to use tail -f with grep to show surrounding lines

I would like to see the output in a logfile greped by only one domain but also the following two lines. Example: tail -f /var/log/apache2/modsec_audit.log |grep mydomain.de this shows all lines, ...
3
votes
4answers
147 views

Identifying genes from a list of genes

I have a gene list file. Some thing like this SWT21 SSA1 NRP1 EFB1 TFC3 MDM10 I have another file which also contains the names of these genes in my list along with other ...
3
votes
5answers
662 views

How can I concatenate a single column of output into a list?

I'm using: ls /proc | grep -v "^[0-9].*" to get a list of all the files and directories in /proc that don't begin with numbers. The output is a single column list, i.e.: acpi asound buddyinfo bus ...
3
votes
5answers
335 views

How to grep, then search and replace on the output?

I have some output from iconv, e.g. $ iconv -l | grep ISO | head -5 CSISO4UNITEDKINGDOM// CSISO10SWEDISH// CSISO11SWEDISHFORNAMES// CSISO14JISC6220RO// CSISO15ITALIAN// durrantm:~ How can I change ...
3
votes
3answers
955 views

How to find first match in multiple files

Is there a way for the find command to search for the first match or occurrence of a string or pattern within each of multiple files? I've been using the usual syntax: find dir -iname '*.ext' -exec ...
3
votes
2answers
11k views

using xargs to grep multiple patterns

I have a file that has terms I want to grep for, with each term being one line in the file. I was thinking I could do this with xargs. What I'm able to glean from examples from the man page like this ...
3
votes
2answers
739 views

Concatenate specific files into one single file

In a folder containing X files, I need to concatenate Y files (where X > Y) together into a single text file. I have the filenames (of Y files) that I need to concatenate. Can anyone please help me ...
3
votes
3answers
3k views

How to search and replace text in all php-files in a directory and it's subdirectories

I am looking for a shell script that recursively traverses all .php files in a directory and performs a search & replace of a particular text pattern. The search pattern is quite long ( > 5000 ...
3
votes
5answers
114 views

How to “grep” a string of a returned result

How to grep the number 50.0 from the string temp=50.0'C In JavaScript I can use the expression /temp=(.*?)'C/ to get it. But I cant get it running in grep.
3
votes
3answers
187 views

Rearrange text file by prepending data rows with header row

I have a file whose content looks like this: 2009 150 0 0 0 0000 75.316 0.0400390625 0.00007 0.00000 0.8980 76.216 0.0400390625 0.00007 1.00000 0.9046 77.217 0.0400390625 ...
3
votes
2answers
182 views

How to use restricted characters in egrep?

I'm trying to use a regex in egrep on Centos 5.10, based on the one I made from this question on SO. T12345 .{1,100}[\n\r].{1,100}2014.03.04 I can successfully match the regex to the content in my ...
3
votes
2answers
599 views

“grep: Unmatched [” error when using regex

I'm trying to find a pattern similar to this: tail -n 100000 gateway.log | grep -B10 -A10 'Nov 22 11:13:56 Received Packet from [10.50.98.68' Where "11:13:56" could be any time. This is what I ...
3
votes
2answers
353 views

grep filter all lines plus one before each hit

I want to parse some output so I exclude all lines that contain either foo or bar, as well as all lines immediately preceding those lines. For example: echo " 1 some line 2 line to exclude because ...