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

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Find which file contain a particular keyword using `grep`

Suppose I know I have to change myhostname = abc.domain.lcl to myhostname = abc.domain.glbl directive but I don't know in which file exactly the directive myhostname is in (i.e., say I have never ...
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How to select specific sets or sturture from a file, if struture contains specific string?

I want to extract the sets with having specific string, for example: file abc.txt contains abc 123 abcd 1234 abcde 12345 abc 123 abcd 123 abcde 12345 abc 123 abcd 1234 abcde 12345 Now from the ...
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4answers
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Use “grep” to match text in multiple files

I have data in multiple files. I want to find some text that matches in all files. Can I use the grep command for that? If yes then how?
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How to show lines after each grep match until other specific match?

I know that by using the "-A NUM" switch I can print specific number of trailing lines after each match. I am just wondering if it's possible to print trailing lines until a specific word is found ...
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How can I recursively grep through several directories at once?

I use grep -r all the time to find occurrences of a string within files in a given directory: $ grep -r "string" app/assets/javascripts > app/assets/javascripts/my_file.js: this line contains my ...
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Capture in shell variables the arguments after a command (between brackets)

Suppose I have a file that contains, among many other things, \command{arg1,arg2,arg3} (arguments been paths, expressed with /, ., characters and numbers) But that a user can as well call it ...
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grep and escaping a dollar sign

I want to know which files have the string $Id$. grep \$Id\$ my_dir/mylist_of_files returns 0 occurrences. I discovered that I have to use grep \$Id$ my_dir/mylist_of_files Then I see that the ...
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is there a way to see a listing of packages ONLY from Debian-experimental?

I am on Debian testing/Jessie and I have debian-experimental as well as in my /etc/apt/sources.list. So I am looking to list packages in two ways :- a. List all the packages which are in ...
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What is the difference between `grep`, `egrep`, and `fgrep`?

Can any one tell me the technical difference between grep and egrep, and fgrep and provide a suitable example? When do I need to use grep over egrep and vice versa?
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Why does regex with \\$\{ work with egrep, but not with sed?

Given a text like this ./RFF_09 -f${FILE} -c${COND} inside a file, this egrep command will correctly match: egrep './RFF(.*) (.*)-c\\$\{COND\}' file but this sed command will not sed -n ...
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Count tabs per line in text file with utils

I have a tab-tabulated file. I would like to check if every line has the same number of tabs. For first step, I'd like to print the number of tabs for each individual line. I've tried grep -o '\t' ...
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grep directory names, filenames, and contents all at once?

I'm writing a module for drupal. Its functionality is contingent on the directory name, certain file names, and function names being identical. I'm troubleshooting now, and I wanted to to a search ...
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249 views

Regex pattern search for alternating character case

How would I pipe the ls through grep to have an alternating character case, as output? For example: I have files (1) aAbBaBbA, (2) bAbBaA, (3) bbAb,(4) AAaBbAa,(5) BBBaaa, and (6) aBaB. I want to ...
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How to use grep and cut in script to obtain website URLs from an HTML file

I am trying to use grep and cut to extract URLs from an HTML file. The links look like: <a href="http://examplewebsite.com/"> Other websites have .net, .gov, but I assume I could make the cut ...
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1answer
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Problem with grep on multiple files and not getting desired output

I am using the below command on a file to extract few lines based on chr# ( different chromosome numbers). This is just a single file am working on. i have 8 such files and for each file I have to do ...
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Why does “grep '.*[s]' file” work and “grep .*[s] file” doesn't?

Comparing grep '.*[s]' file with grep .*[s] file Why do you need quotation marks to let this work properly? In the second case, grep seems trying to inspect every file with a period.
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How to return 0 if a pattern is matched from a file? [duplicate]

I have a binary that repacks android kernel (not mkbootimg). I'm making a script to automate the process. I don't want any output on the screen. So I have redirected the output to a file named ...
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fgrep beginning of line?

I'd like to use fgrep to handle searching literal words with periods and other meta-characters in grep, but I need to ensure the word is at the beginning of the line. For example, fgrep 'miss.' will ...
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How do I grep on a live log (stdout)?

I'm not sure if that what stdout is, but that's what I think. What I want to do is filter out a certain log message when running an executable. I tried this: Executable 2>&1 /dev/null | ...
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3answers
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How can I insert the contents of a file into a string in bash

I would like to append the contents of a multi-line text file after a particular line in a string. For example, if the file file.txt contains line 1 line 2 I'd like do so something like printf ...
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Group matching with grep includes extra characters

I wanted to extract some text with regex in bash, so I decided to try the following simple example out. echo "abc def ghi" | grep -Po " \K(.*?) " I was expecting to get a "def", but to my surprise ...
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Show exact number of CRLF occurrences in file

grep -c $'\r\n' file returns the exact same number as grep -c $'\n' file, it shows the number of LF in the file instead of the number of CRLF. (The file definitely does not contain that number of ...
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264 views

How to do a netstat that will only filter based on pid

How can I have the following command below just show/filter based on the PID's I'm looking for? sudo netstat -lp --inet The results come back as this Proto Recv-Q Send-Q Local Address ...
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grep inside less?

I'm currently sifting through a lot of unfamiliar logs looking for some issues. The first file I look at is Events.log, and I get at least three pages in less which appear to display the same event ...
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How can I prevent 'grep' from showing up in ps results?

When I search for some process that doesn't exist, e.g. $ ps aux | grep fnord wayne 15745 0.0 0.0 13580 928 pts/6 S+ 03:58 0:00 grep fnord Obviously I ...
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How do I make an output for grep fail?

I am using if-else statement to search for keywords and displaying the results in the terminal, here's an example of my code. read finding if ["$finding" != "" ]; then grep $finding ...
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Why recursive grep does not work with STDOUT? [closed]

I've been long used to have some custom aliases in my Ubuntu/Mint machines, like alias grep='grep -irn --color --line-buffered'. However, I've noticed that since a while ago this stopped working for ...
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grep files from list

I am trying to run grep against a list of a few hundred files: $ head -n 3 <(cat files.txt) admin.php ajax/accept.php ajax/add_note.php However, even though I am grepping for a string that I ...
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what is grep -v -f /dev/null expected to do exactly?

Theory: grep -f somefile or grep --file=somefile will find all lines that match one of the patterns listed in somefile. If somefile is empty, nothing will match. With grep -v you list lines that do ...
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counting occurrences of a string

I have a large database of this format: 0500506 gi|561108321|ref|NC_018143.2| 71446 0 0500506 gi|561108321|ref|NC_018143.2| 71447 0 0500508 gi|561108321|ref|NC_018143.2| 71449 0 0500509 ...
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Different usage of grep

I know grep can be use to do partial search, for example if i use echo "Enter example" read example echo "Enter Subject" read subject grep -i ^$example info.txt | grep -i ^[^,]*:$subject The ...
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Extract substring using regular expression on a Unix file

I have file with below contents . /ABC/RTE/AD_900_VOP_123/OPP /ABC/RTE/TRE/AD_900_VOP_145/BBB /ABC/RTE/AN_900_VFP_124/FBF /ABC/RTE/HD_900_FOP_153/WEW /ABD/RDV/AD_900_VOP_123/OPP ...
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egrep for specified strings and newline

I receive a prespecified list of strings. In a number of textfiles (example below), I want to search for strings, that do not start with one of the strings in the list. From time to time, a blank link ...
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Pattern Search between specific lines and print line numbers

I have a file of 20 lines. I want to search for a string between the lines 10 and 15 and print the string along with the line numbers of the original file. I have tried sed -n 10,15p file | grep -n ...
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grep skip n lines of file and only search after

I have a huge log file and want to grep the first occurrence of a pattern, and then find another pattern right after this occurence. For example: 123 XXY 214 ABC 182 558 ABC 856 ABC In my example, ...
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How to use Cut and Grep command to find data separated by “:” [duplicate]

In my simple database, it contains text of like, example, soldiers. Name:Rank:Gender:Age:Years of Service Tom Corporal:Recruit:Male:19:2 Nicole Sergeant:Corporal:Female:30:10 Daniel ...
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How can I find all files that do NOT contain a text string?

What concise command can I use to find all files that do NOT contain a text string? I tried this (using -v to invert grep's parameters) with no luck: find . -exec grep -v -l shared.php {} \; ...
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Using grep for listing certain lines from a file

Using a random file, such as /usr/share/vim/vim74/tutor/tutor, is there a way to list all lines that start with a 5 letter word ? How about the lines that end with a 5 letter word ? I've been ...
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How do I make grep list the count of matches before the filename?

grep -cZ has the weird behaviour that, while filenames are nul-terminated, the count of matches appears after the corresponding filename. Via od -c: 0000000 / u s r / i n c l u ...
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How can I teach grep to treat properties-files like text-files

Since I upgraded grep from 2.16 to 2.21 it treats .properties-files like binary files. This sucks because I like to use grep -I ... to exclude binary files from the search results and ...
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How to use grep and cut together?

Lets say I'm doing a database for fruits. Using a text file for it, inside contains, in this format, (Fruit:Quantity:Cost) Apple:10:1 Orange:20:2 Pears:10:3 Banana:20:4 10 Apples at $1 each. 20 ...
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2answers
57 views

find and replace a value in a line of text

I have a text file which contain only 1 line of text 1314:Battery:1.90:50:30 I'm trying to figure out if is there anyway to do a grep and sed to change the value 50 and 30 to the following ...
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Select lines starting with specific numbers

I have to show the PID, PPID and STATUS of the procceses on the system, but only the ones which PID starts with numbers in the range 5-8. So i tried something like this... ps xao pid,ppid,s | grep ' ...
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How to make a filter more efficient

I've created a script to compare a list of users from a MSSQL database against a list of disabled AD users. The tool we use for AD authentication returns data in the following format (with plenty ...
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Why the grep result depends on folder path? [duplicate]

I meet a strange phenomenom when using grep on Solaris 10: I try to use grep to find creat related DTrace probes. When in a folder (/data1/nan), it works OK: bash-3.2# pwd /data1/nan bash-3.2# ...
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extracting lines from a large text file

I have a text file with data that looks like this (1875 lines to be exact) chr1 MOTEVOC_cage_181208 TF_binding_site_cage_181208 6585538 6585547 0.905022147 - . TF_binding_site_cage_181208 ...
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1answer
27 views

output neighbouring lines with line numbers while grepping

Is there a way to output the neighbouring lines along with the line numbers while grepping the contents of a file? I'm trying to get outputs of the form: $ ~/myscript.sh download file # 'download' ...
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1answer
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grep stopped working [closed]

This is a weird question. I was using the normal grep -w command to search through millions of lines to extract specific lines that contained the word that I was interested in. grep -w Search_word ...
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575 views

grep with logic operators

Is there a grep-like utility that will enable me to do grep searches with logic operators. I want to be able to nest and combine the logical constructs freely. For example, stuff like this should be ...
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Reverse match in sed, replace opposite of what was found

Say I have this output from my syslog, precalculated src_hash => 20 bytes @ 0x7f811c001e20 A6 2D E5 CD 2A BA F0 42 56 66 19 D4 61 1A E3 A0 .-..*..BVf..a... C7 5E 5F 77 ...