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

learn more… | top users | synonyms

54
votes
7answers
14k views

Is there a basic tutorial for grep, awk and sed? [closed]

I've been a Linux user for a while, and I've a pretty decent understanding of most the common command line utilities. However, ones that come up and up again in relation to programming are grep, awk, ...
-1
votes
1answer
56 views

How to use grep to filter out lines starting with any of a set of keywords?

I have a large file (a chemical database), and I need to display only header records, which are defined as lines that don't start with: ATOM, CONNECT, HETATM, TER, or END. I'm supposed to use grep to ...
3
votes
4answers
124 views

Test if command accepts a specific option

What is the preferred way to test if a command takes an option? What are the caveats? As a motivating example, at login my shell aliases grep to add several --exclude-dir options but this option is ...
1
vote
1answer
41 views

Store output from one command and process it for another

I am working on Unix command line. I have two files. I want to cat file1.txt and grep the output in file2.txt File1.txt 123A 223A 143A 153A 183A 123J 123P File2.txt: 123A (TYU) 223A (RUT) 143A ...
3
votes
1answer
44 views

Extract csv files from path to multiple files in bash

I have a files multiple file path for backup purpose ,now i want to filter it based on ".csv " fromat. I have tried this. filesall=(/home/abc/allfiles/*) files=$((${filesall[@]}|grep -F ".csv")) ...
-2
votes
2answers
49 views

Grep and cut the selected field

I am trying to cut the field if a line starts with a particular name, cat $1|while read line do if [ "$1" = "custbills.cmp" ]; then acc_no=`grep "^Custbills" $1 | cut -c29-43` acc_type=`grep ...
1
vote
1answer
36 views

Find files in multiple directories taken from list in a file?

FreeBSD 9.2 RELEASE p2 I have a file dirs.txt. In this file is a new line separated directory list like so: /etc /home /home/goods/ I need to first find in all directory's files which have names ...
1
vote
4answers
46 views

Parsing complex text file using Unix commands

I have the following text structure which I would like to parse: >Cluster 423 0 56aa, >HWI-ST1448:257:C3V2HACXX:1:1106:19087:2550.1... at 92.86% 1 64aa, ...
4
votes
2answers
371 views

how to make alias to make grep command shorter [duplicate]

In my coding, I always do grep -rnIi "abcabc" . --color But, how to make an alias that can let me type only one word with my search string? Is that possible?
2
votes
2answers
32 views

Use awk to find first occurrence

I have a log file that gets updated when my script runs. The script will insert "Start of script" text when it starts and "End of script" text when it finishes running. I am trying to capture the ...
2
votes
3answers
64 views

Count of several keywords on a site

I currently have the following command wget -O - -q http_url_goes_here | grep -Eci '(cart|shop|buy|order|store|shipping|products|price)' It gives me a count of ALL occurences of each of the ...
1
vote
2answers
57 views

grep works fine in command line but returns nothing in script

I'm trying to write a small script to get me list of files that match certain criteria into a file. #!/bin/sh cd /var/www_data/patch/ grep --include=\*.{php,ini,conf,sh} -ril -P ...
3
votes
3answers
100 views

Replacing string in all files found by grep. Can't get it to work

I'm trying to do what title says. So I find all needed files with grep: grep --include=\*.{php,ini,conf,sh} -ril -P "'([\d\w\-\_\.]+)(@domain.com)'" '/var/www_data/somepath/' Now I assume it's ...
5
votes
4answers
324 views

How to add a carriage return before every newline?

I have a file that only uses \n for new lines, but I need it to have \r\n for each new line. How can I do this? For example, I solved it in Vim using :%s/\n/\r\n/g, but I would like to use a script ...
4
votes
4answers
138 views

extract lines according to a particular column

I have a CSV file like CK,ck XYZ,xyz,xyzs ABC,abc,abcs PQR,pqr,pqrs LMN,lmn, IJK,ijk, I have to check if something is written in column 3 except whitespace, then display the whole line.the output ...
4
votes
4answers
42 views

regexp which matches all tokens independent of order

I have a quick (and hopefully simple) question about regexps. I'm trying to think of a regexp which matches all of a set of tokens irrespective of order. So for example I have a file with the names ...
30
votes
4answers
2k views

Reverse grepping

Let's say, I have a really big text file (about 10.000.000 lines). I need to grep it from the end and save result to a file. What's the most efficient way to accomplish task?
0
votes
1answer
26 views

Improve execution time for recursive md5sum check?

This recursive md5sum check for 40000 items of 11.8 GB takes 2 minutes: ret=$(find "${target}"/ -name ".md5sum" -size +0 | while read aFile; do cd "${aFile%/*}"; md5sum -c ".md5sum"; done | grep -v ...
1
vote
1answer
35 views

ls and find command excluding a certain directory

I want to do this: ls -altrhS 'find / -type d \( ! -name tmp -prune \) -size +10000k 2> /dev/null -print' | egrep -v 'ibd|MYD|MYI' So I want to list, in that format, files of a specific size ...
5
votes
7answers
503 views

How to find a position of a character using grep?

I need to identify the postion of a character in string using grep command. Example, the string is RAMSITALSKHMAN|1223333. grep -n '[^a-zA-Z0-9\$\~\%\#\^]' How do I find the position of | in the ...
0
votes
1answer
80 views

Grep a string with spaces from a file

#!/bin/bash LIST=/errors_exception.txt cd /test for PATTERN in `cat $LIST` do for FILE in $(ls) do if zcat $FILE | grep -Fxq "$PATTERN"; then echo "$PATTERN found ...
3
votes
3answers
179 views

Get the part of a line before the last slash

I'm trying to write a conky script that shows my MPD album art, a 'folder.jpg' in the album folder. My current plan is to use mpc -f %file%, which prints out the file name and path, and then cut out ...
2
votes
4answers
242 views

Only cat from specific line X (with a pattern) to other specific line Y (with a pattern)

A little extended problem from "cat line x to line y on a huge file": I have a huge file (2-3 GB). I'd like to cat/print only from the line having "foo:" to the line having "goo:". Assume that "foo:" ...
-1
votes
2answers
34 views

Searching out a pattern from Logs

The format of the logs is in this manner: Junk Junk Junk : Junk Junk Junk:IP/Port Junk Junk I want to search using the IP and the output should be only the IP/Port part of each line in that log ...
11
votes
3answers
2k views

Online grep exercises?

Are there any online grep tutorials that would feature some online tool for performing exercises? For example, having some predefined text sample and being told what patterns to find and so forth? It ...
20
votes
6answers
4k views

Regex for all 10 letter words, with unique letters

I am trying to write a regex that will display all words that are 10 characters long, and none of the letters are repeating. So far, I have got grep --colour -Eow '(\w{10})' Which is the very ...
2
votes
2answers
31 views

Live replacement, while viewing log using LESS

It's very convenient to monitor logs using less command - you see what is going with your system as it happening. The bad thing is that my logs are optimized for grep tool: each atomic action is ...
1
vote
1answer
673 views

grep IP addresses in expect script

This is part of code in an expect script, I have a problem with searching IP addresses from a file whose name is in the variable $filename. #!/usr/local/bin/expect -- ###Made by Etihkru#### set ...
0
votes
1answer
161 views

How to execute grep in tcl for getting XYZ-123 type pattern

How can I execute this grep command in TCL? grep '[A-Z][A-Z][A-Z]\-[0-9][0-9][0-9]' file1 > file2
9
votes
2answers
28k views

Return only the portion of a line after a matching pattern

So pulling open a file with cat and then using grep to get matching lines only gets me so far when I am working with the particular log set that I am dealing with. It need a way to match lines to a ...
0
votes
1answer
17 views

find file read it and search for specific identifier

I'm trying to find out in what files some specific identifiers are being used. I know the file's name and know the identifier, therefore I use the following command to achieve my desired result: find ...
1
vote
3answers
61 views

Detecting extension files doesn't executed for a period

How can I detect the .class files in my workspace which haven't executed for a certain period, and remove them?
2
votes
5answers
140 views

Remove multiple lines after a pattern match but only after pattern match

I am trying to remove all instances of a pattern match from a file if it matches a pattern. If there is a match, the (complete) line with the matching pattern and the next line get removed. The next ...
1
vote
2answers
57 views

grep contents of files based on a list of files

Running CentOS 6.5, qemu-kvm. I have a script which builds a list of running VM's. I want to pull information from those .xml files of only the VM's that are running. cat /dev/null > ...
8
votes
7answers
361 views

How can I “merge” patterns in a single line?

I am doing grep and sed and I get 2 lines of a file that I am interested in. How can I get these lines in a single line ending with the new line character? Now I am getting: pattern1 pattern2 ...
3
votes
2answers
295 views

Searching for string in files

Is there an easy way to search inside 1000s of files in a complex directory structure to find files which contain a specific string within the file?
0
votes
2answers
35 views

grep command. '^1' won't work

ttys000 -bash: cat n_modified.txt 1 calibre library 2 desktop 3 documents 4 downloads 5 library 6 movies 7 music 8 pictures 9 public 10 ...
4
votes
5answers
414 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 ...
3
votes
4answers
79 views

How to remove text matching specific patterns from a file

I want to compare two files to check for differences between them, fileA and fileB. fileA is like a template file and fileB is the file which I want to compare to it. Anytime I find a difference I ...
0
votes
0answers
22 views

How to get ids from xml file into mysql?

I've got 8 xml files and need to do some work on these records in mysql. What is a good way to get these IDs into mysql? <?xml version="1.0" encoding="utf-8"?> <Records> <Record> ...
2
votes
1answer
41 views

Grep does not seem to work properly for me

Command: LC_ALL=C fgrep -f /root/inputfile.txt *.txt > outputfile.txt inputfile contains this kind of stuff; -name1: -name2: -othername: *.txt (multiple files) contains things such as ...
2
votes
1answer
5k views

Read log file between two dates

I have to read log file between and my question is how to get only the text in the file wich is between two dates using unix commands? Every line contain date and I want to get the text in the file ...
17
votes
6answers
853 views

How can I highlight matches using GNU grep?

I have seen on some Linux, that grep is configured to highlight the match, and print the matching file. How can I configure grep to highlight matches?
2
votes
1answer
24 views

Get each column which contains multiple spaces?

My file: subnet 172.25.10.0 netmask 255.255.255.0 { option domain-name-servers 172.25.10.9, 8.8.8.8; default-lease-time 300; max-lease-time 7500; range dynamic-bootp 172.25.10.10 172.25.10.30 ; ...
0
votes
1answer
37 views

Quote escaping struggle with grep and sed

I'm writing a bash script to extract data from html tags and I found this command in another thread : grep -o '<tr>.*</tr>' HTMLFILE | sed 's/\(<tr>\|<\/tr>\)//g' > NEWFILE, ...
5
votes
4answers
77 views

Search a pattern and print preceding lines starting with another pattern

I need to grep for a pattern and once I find it, I need to look for another pattern preceding that and print all those lines in between those. Better example: 1 a 2 a 3 a 4 a 5 a 6 b 7 c 8 d 9 xyz ...
-4
votes
1answer
81 views

What command in bash to search for this string?

file.txt contains: aa=testing sss=whoiam bbb=findme What command do I use to search for testing and print it? Expected result: # you search testing
4
votes
1answer
65 views

unexpected output with grep

I am using pyrit. For those who dont know, pyrit allows among other things to check if a wpa handshake key is valid: pyrit -r file0.cap analyze when a file does not contain a valid key, here is ...
4
votes
6answers
159 views

grep with a lot of files which contains a lot of lines?

Imagine we have a lot of huge(30000 line)files: a.2014-05-06, a.2014-05-07, a.2014-05-08 and so on. I know that we can grep a line with word using this command: grep "word" a.* First I guess this ...
3
votes
2answers
85 views

Getting the combined count of all occurences of a string under multiple directories?

I have a (hopefully) interesting problem that I could use some advice on. I have a system that's essentially used for storing logs. It has a directory structure like: YYYY/MM/DD/hostname/ There are ...