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

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Strings enclosed in '' are ignored when using grep

When I tried searching for a string within a file, the results didn't include those that were enclosed in single quotes. For example: grep -rn text folder/ The results didn't include strings the ...
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Find the files between two folder dates in linux?

I need to find the folder names along with the file names which has my string in their contents. I am in this directory "/data/queue/data" and I have lot of folders in the same directory and inside ...
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Limit grep context to N characters on line

I have to grep through some JSON files in which the line lengths exceed a few thousand characters. How can I limit grep to display context up to N characters to the left and right of the match? Any ...
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Filtering the result of the find command, so that it returns only directories

Is it possible to get only the results from find that are directory paths? Using find with some option, or using grep or some other utility the results are piped into as a filter? I thought something ...
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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 ...
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Trouble with grep -o regex

I'm trying to use a grep command with the --only-matching flag, but it's not behaving as I would expect it to. This command: echo "1/2/3/4/5" | grep -oE "^([^/]+/){0,2}" Gives this output: 1/2/ ...
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Regular expression to match sequences of alphanumerics

Any way using grep/awk/perl to match lines in the form *.* = *.* (i.e. ac4df.bx5dfd8g = ce5def.dd5f7gdgf ) Where * means 0+ alphanumeric char?
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Error getting the string between two patterns

I want to get a string between two patterns. The pattern is the first environment <p> </p> in an html file. <p>Sorcery, R (1) </p> <p ...
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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 ...
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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 ...
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How to trick an init script into returning 0

I have a init script which is poorly designed because it does not conform to the Linux Standard Base Specifications The following should have an exit code of 0 if running, and 3 if not running ...
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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 ...
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Escaping of meta characters in basic/extended posix regex strings in grep

Is it possible to escape all meta characters of a string inside a variable before passing it to grep? I know similar question has been asked before on SE (here) and also a good explanation here, but I ...
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Print repeating pattern

I have a marathon file from which I want to print the names of the runners, who have made multiple runs. Something like: M, 2:08:58.0, John Lukas, USA, 1997-07-25, Paris, France F, 2:15:04:0, Abebbe ...
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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 ...
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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 ...
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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). ...
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Optimizing a shell script with long running while loop

I have written a shell script which has to do the following: Capture session commands into one file. Every individual command into separate file. Mail every individual command file content based on ...
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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 ...
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563 views

Most efficient grep method

Currently I am grepping data from a file containing any of the following: ...
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6k 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" {} \; | ...
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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 ...
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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: ...
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Grep: search and replace full line

The command grep "foo" myfile.txt prints all matching lines in my file. Now I want to replace the full line with another string. How can I do that?
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How to “grep” for line length in a given range?

I need to get only the lines from a textfile (a wordlist, separated with newline) that has a length range of minimum or equal than 3 characters, but not longer or equal then 10. Example: INPUT: ...
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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 ...
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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 ...
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What's the difference between \b and \< in the grep command

In the man page of grep, I see The symbols \< and \> respectively match the empty string at the beginning and end of a word. The symbol \b matches the empty string at the edge of a ...
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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 ...
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877 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 ...
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GNU Parallel - grepping n lines for m regular expressions

The GNU parallel grepping n lines for m regular expressions example states the following: If the CPU is the limiting factor parallelization should be done on the regexps: cat regexp.txt | ...
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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 ...
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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 ...
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grep --include acts like --exclude

I'm trying to make use of the --include option of grep, but it doesn't behave as I expect. Consider this simplified test: Setup me@de31:~/tmp$ cat file.h This is a .h file me@de31:~/tmp$ cat file.c ...
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ack.pl tool and ack.pl flags

I am using the ack.pl tool in order to search string or IP’s in files The official site of ack.pl is - http://beyondgrep.com/documentation/ Example of ack.pl CLI ( want to find the string ...
4
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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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How to exchange words in a filename using the shell?

One of my customers is a school. On their file server all projects have a directory with the same naming scheme. <last name>, <first name> <second name>? - <project ...
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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 ...
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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 ...
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How to grep the n-th substring between given delimiters?

Let's say we have a string and its delimiter is ?: Leslie Cheung April 1 ? Elvis August 16 ? Leonard Nimoy February 27 I know how to grep the first substring between delimiters: echo $above_string ...
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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 ...
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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.
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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 ...
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4answers
250 views

Grep pattern inluding dashes and restricting to a filename extension

I am trying to use grep to find some tex files containing the pattern ->-: grep -R -- "->-" *.tex But this doesn't work. If I do: grep -R -- "->-" instead, it works, but is really slow ...
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2answers
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grep on a variable

Lets say I have a variable line="This is where we select from a table." now I want to grep how many times does select occur in the sentence. grep -ci "select" $line I tried that, but it did not ...
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How can I filter those “Permission denied” from find output? [duplicate]

I started using sed recently. One handy way I use it is to ignore unimportant lines of a log file: tail -f example.com-access.log | sed '/127.0.0.1/d;/ELB-/d;/408 0 "-" "-"/d;' But when I try to ...
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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, ...
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How can I delete all text between curly brackets in a multiline text file?

Example: This is { the multiline text file } that wants { to be changed } anyway. Should become: This is that wants anyway. I have found some similar threads in the forum, but they don't seem ...
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How to use the grep result in command line?

When I use grep to find some text which I need, it will display lines containing a match to the given pattern. For example, # grep -r ".*Linux" * path0/output.txt:I hope you enjoyed working on ...
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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 ...