Questions tagged [grep]
grep is a Unix command-line utility that searches input for lines matching (or not) a regular expression and prints the results. Use this tag for questions about how to use grep features, how to write regular expressions that work with grep, and general usage. Because grep is now available in Unix-like environments (e.g., Cygwin on Windows), you can also use this tag for compatibility questions, and differences between versions and software environments.
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Getting colored results when using a pipe from grep to less
I use the --colour option of grep a lot, but I often use less as well. How can I pipe grep results to less and still preserve the coloring. (Or is that possible?)
grep "search-string" -R * --colour | ...
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votes
14
answers
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Grep equivalent for Windows 7?
Is there a command prompt grep equivalent for Windows 7? That is, I want to filter out the results of a command:
Bash use:
ls | grep root
What would it be from a Windows command prompt?
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votes
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Using watch with pipes
I'd like to run this command:
watch -n 1 tail -n 200 log/site_dev.log | grep Doctrine
But it does not run, because "I think" that the grep tries to run on the watch instead of the tail...
Is there ...
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votes
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answers
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How to find uptime of a linux process
How do I find the uptime of a given linux process.
ps aux | grep gedit | grep -v grep
gives me a whole lot of information which includes the time at which the process was started.
I am specifically ...
- 1,043
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votes
9
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grep to find files that contain ^M (Windows carriage return)
I use Linux. There is a pesky ^M (Windows cariage return) somewhere hidden in thousands of configuration files, and I have to find it, because it makes the server fail.
How do I find ^M among a ...
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votes
3
answers
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How to use 'sed' with piping
I want to replace a string outputted from grep, I have:
$ npm info webpack | grep version
it outputs me
$ version: '2.1.0-beta.12',
but I want to have:
$ 2.1.0-beta.12
So I think I might ...
- 1,035
89
votes
8
answers
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Display all output but highlight search matches
In bash, if I want to execute a command and only display output lines that matches a certain pattern, I can pipe it to grep, like
file testfile
hello
there
my
friends
command
$ cat testfile | grep '...
- 4,291
87
votes
22
answers
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Monitoring a file until a string is found
I am using tail -f to monitor a log file that is being actively written to. When a certain string is written to the log file, I want to quit the monitoring, and continue with the rest of my script.
...
- 1,531
72
votes
4
answers
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Grep-like functionality for Notepad++?
I would like to have some grep-like functionality in Notepad++.
In it simplest version, I would like to be able to copy all lines from the current buffer that contain the word foo to a new buffer. I ...
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votes
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answers
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How can I "grep" recursively filtering the name of the files I want with wildcards?
When I want to perform a recursive grep search in the current directory, I usually do:
grep -ir "string" .
But that command searches inside all kinds of files, including binary files (pictures, ...
- 1,730
68
votes
4
answers
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Powershell equivalent of `grep -r -l` (--files-with-matches)
In Powershell, how do I list all files in a directory (recursively) that contain text that matches a given regex? The files in question contain really long lines of incomprehensible text, so I don't ...
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Can GNU Grep output a selected group?
Is it possible to use GNU grep to get a matched group from an expression?
Example:
echo "foo 'bar'" | grep -oE "'([^']+)'"
Which would output "'bar'". But I would like to get just "bar", without ...
- 958
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votes
1
answer
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What is the difference between grep, pgrep, egrep, fgrep?
I'd like a walk through on the differences between grep, pgrep, egrep, and fgrep and how I would use them.
- 7,058
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how to grep and print the next N lines after the hit?
I would like to grep for an occurrence in a text file, then print the following N lines after each occurrence found. Any ideas?
- 4,427
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How can I grep with color in Mac OS X's terminal?
I recently found that on Mac OS X I can set this up in my shell ~/.profile so that when I use grep it will print the matches in color (white one red).
alias grep='GREP_COLOR="1;37;41" LANG=C grep --...
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grep for "term" and exclude "another term"
I am trying to build a grep search that searches for a term but exludes lines which have a second term. I wanted to use multiple -e "pattern" options but that has not worked.
Here is an example of a ...
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recursive grep: exclude specific directories
I use recursive grep a lot to find source files with specific content.
grep -Rni "myfunc" .
On large codebases, this can get slow, so I use --incldue to restrict/whitelist extensions.
grep -Rni --...
52
votes
3
answers
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find / grep command without searching mounted shares
When I used the find command, I almost always need to search the local drives. But, I almost always have super large network shares mounted and these are included in the search. Is there an easy way ...
- 1,643
41
votes
5
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Writing "tail -f" output to another file
As a continuation from my last post where I have used grep & tail -f to find occurences of "rare" events. I would like to record this in another file.
I've tried turning
tail -f log.txt | ...
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13
answers
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What regular expression can I use to match an IP address?
With the following grep syntax I want to match all IP address in a file (from a ksh script)
grep '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' file
The problem: It also matches words (...
- 1,127
33
votes
1
answer
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Combine tail -f with grep?
Hi I wanna keep looking at a log file, but I also don't wanna see irrelevant stuff, I'm only interested in anything with "foobar" in it.
So if I was tailing the file I would do
tail file | grep "...
- 1,227
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votes
3
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Counting total number of matches with grep instead of just how many lines match
Does grep offer a way to count the total number of matches it makes? The -c option only returns the number of lines that matched the regex, but in this case I have multiple matches per line.
- 557
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votes
18
answers
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List only the device names of all available network interfaces
I want to get a list of all available Network-Device Names on my Linux server. I figured that
ifconfig
would do the job, however ifconfig produces quite much output:
eth0 Link encap:Ethernet ...
- 593
30
votes
7
answers
36k
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Excluding grep from process list
I have cobbled together a command to return the process ID of a running daemon:
ps aux | grep daemon_name | awk "{ print \$2 }"
It works perfectly and returns the PID, but it also returns a second ...
- 303
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votes
3
answers
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How do I pipe output to date -d "value"?
I have a date like 2014-01-30 05:04:27 GMT, and if I run date -d "2014-01-30 05:04:27 GMT", the output is in my server's timezone (Thu Jan 30 16:04:27 EST 2014).
With the use of grep and cut,...
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Can grep show context, but not a full line?
I have a file with several very long lines. I want to grep for a string which may occur several times in the file, including possibly more than once on the one line.
$ cat 2014-11-03.json | grep 218
...
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Command-line CSS selector tool [closed]
Question
What tool (preferably for Linux) can select the content of an HTML element based on its CSS path?
Example
For example, consider the following HTML document:
<html>
<body>
&...
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In Unix "less", can I jump to the next line that does NOT contain X?
In the Unix less tool, is it possible to jump to the next line that does not contain a certain expression?
I sometimes have to look through files that contain thousands of similar adjacent lines ...
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Grep tool for XML [closed]
I am looking for a good tool to perform grep-like operations on XML - for example, extract certain attributes only.
Grep itself can't handle it - any DFA-equivalent tool can handle only non recursive ...
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3
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How to grep a log file within a specific time period
I have a log file, each line in the log is prepend with a date, like so:
2012-03-06 11:34:48,657 blah blah blah...
How do I grep this file and get only the lines from 8am to 11pm only?
My ...
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How to find file with name="php.ini" on linux using grep command
How to find file with name="php.ini" on linux using grep command ? Can anybody show me ?
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Recursive zgrep not working
I have a directory hierarchy that contains numerous .gz files. I want to be able to recursively grep them for the string "foo". From what I've read online the following should work:
zgrep -R -H "...
- 1,011
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Advantages of cat'ing file and piping to grep
Are there any additional advantages of cat'ing a file and piping it to grep, besides convenience? The convenience being that, when I retrieve commands such as those below from my history, the cursor ...
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How to prevent a password or other sensitive information from being stored in the bash history when using grep?
I had to grep recently for a password that may have been saved in a file. I did not want that line to show up in the bash history.
How can I prevent a password or other sensitive information from ...
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3
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How to Combine find and grep for a complex search? ( GNU/linux, find, grep )
I'm trying to do a text search in some files that share a similar directory structure, but are not in the same directory tree, in GNU/Linux.
I have a web server with many sites that share the same ...
- 3,883
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votes
1
answer
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does grep regex work differently on mac?
Just trying to figure out basic use of regexes with grep (or egrep) in mac terminal (BSD grep - 2.5.1-FreeBSD).
File to examine (pow.txt) contains the lines :
kiytytytyty
and
blob.mkv
command ...
- 323
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votes
5
answers
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Ubuntu grep, find etc: "Permission denied" and "No such file or directory" output
When I use grep or find, I always get annoyed by the "Permission denied" and "No such file or directory" notices, something like this:
johndoe@johndoe-desktop:/$ grep -rnP 'YII_CORE_PATH' ./ | grep -...
- 353
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5
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How to combine wget and grep
I have a html-page url and I want to grep it. How can I do it by wget someArgs | grep keyword?
My first idea was wget -q -O - url | grep keyword, but wget's output bypass grep and arise on the ...
- 1,177
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ack-grep show the matched files name only. Do not show the matched content
I'm searching some keywords among minified files.
It doesn't make sense to show those minified content.
How could I use ack-grep 'SEARCH_WORD' and show the matched file names only
- 684
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regex : does not begin by "pattern"
I have a lot of lines in my LIST file and want to list only lines whose name does not start by (or contains) "git".
So far I have :
cat LIST | grep ^[^g]
but I would like something like :
#not ...
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Edit first line of large text file
I have a huge text file, far too big for the whole thing to be paged into memory. All I need to do with this text file is edit the first line (its a CSV file and I need to alter the titles).
Is there ...
- 1,871
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Ubuntu Linux: find files between specific times?
I found an SO called using Find/Grep to search files between specific time of day
Based on that and a Unix SE called Grep command to find files containing text string and move them I ended up with:
...
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How do I search for a string in a PHP file using `grep`?
I am searching for a class declaration on a site with hundreds of PHP files. How can I do this in the current folder and subfolders using grep?
I tested cding to the folder and then something like
...
Sam3k
18
votes
4
answers
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How to use ack to search for file name
I have started using ack which is much faster than grep. However using ack I want to search for file name rather than file contents. Is there a way to do that?
- 959
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3
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Finding and deleting lines from all files recursively
I have managed to grep the occurences of a keyword by using
grep "KeyWord" . -r -n -i -I
but, the occurences of the KeyWord are too large. I just want to delete all the lines containing that word.
...
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3
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Grep default color option
grep is one of the most commonly used command in linux. It feels to me that its basic feature to highlight the string you searched for on the output lines. this can be achieved by --color option.
...
18
votes
3
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How to have grep print only the matching text plus X surrounding characters
I need something similar to grep -A and grep -B but for characters. In other words, I have a file with incredibly long lines, e.g.:
[thousands of characters] mytext [thousands of characters]
If I do ...
- 2,395
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3
answers
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Manually select/unselect lines before forwarding to stdout
Is there any way to grep interactively, meaning that I have a bunch of lines coming from somewhere that I want to pipe to further processing, with the option to manually specify the lines I want?
...
- 1,527
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votes
7
answers
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How to list all source files (*.c, *.cpp, *.h)
I'd like to find source files (*.c, *.cpp, *.h) that contain in Linux/MinGW/Cygwin, and recursively in all sub directories.
My basic idea is using find and grep. However, building a regular ...
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grep changing the delimiter
any way we can change the delimiter that uses grep?
I think, by default, grep uses \n as the delimiter.
jhon