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

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Escaping * with Regular Expressions and Grep

I have a file that has unique lines that start with 2 stars (**). However when I run a grep command for grep \*\* fileName I get all of the lines in the file. This is very unusual, and what I ...
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Faster way to find matching patterns from external file grep -f {patternfile} {source} in BASH

In *nix terminal (Bash) os there any other faster way to find a pattern (or excluding them - egrep -v option) than using this: grep -f {patternfile} {source} Using this option is painfully slow for ...
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How to grep the last number on a line in a bash script

I have output from the smartctl -a command; one of the lines looks like this: 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 301 I've placed this into a variable (if that's the correct term) ...
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Print a text file from a line number to another after searching for the lines

I want to print a text file from X line number to Y line number The value of X & Y is determined by searching for a specific line in the text file(in this case the page number) I search for the ...
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1answer
112 views

Numbering the output of grep

When we're filtering the output with grep, is there any way we can get line numbered output, like we get with cat -n? I'm not asking for the grep -n option which shows the line number of the match in ...
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1answer
407 views

Stream grep from subprogram, not tail file

Does a simple one liner exist for grepping continuous output from a program rather than just a file? Now just as an example, I would like to skip lines containing PHPUnit in them. For obvious reasons ...
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949 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 ...
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Some UTF-8 characters not being recognized by grep or sed

Trying to determine all characters in a file. The file sample consists of: a eɪ abandon əˈbændən ability əˈbɪləti able ˈeɪbəl able ˈeɪbl abortion əˈbɔrʃən abortion əˈbɔrʃn about əˈbaʊt above əˈbʌv ...
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1answer
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if condition, loop in grep [closed]

Could someone please provide help for me. I tried to start writing a shell script but am getting hung up with this issue. I need to grep commands "adb shell ps" and find in it 3 processes with names: ...
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2answers
559 views

Grep a string from file

I have 5 filenames created inside a folder for one operation.The filenames are in the following format. ES_currentdate_currenttime_processid_uniqueid.log I want to read the status from the latest ...
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How to find multiple strings in files? [duplicate]

I use the following command to find files with a given string: find /var/www/http -type f | xargs grep -iR "STRING1" But how can I find files which include "STRING1" OR "STRING2" OR "STRING3"? ...
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Grep in couple thousands files

I have directory with cca 26 000 files and I need to grep in all these files. Problem is, that I need it as fast as possible, so it's not ideal to make script where grep will take name of one file ...
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5answers
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grep for multiple strings in files, and then list the files in the order of size

I am in a folder with lots of .txt file, I would like to find all the files which contain both stringA and stringB (not necessarily on the same line), then list these files in the order of the size ...
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1answer
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Piping search term (not filename) to grep

I want to pick out certain lines containing a given number from a file. The file I want to search is called os_clusters/piRNA_clusters.bed. awk '{if (a[$0]++ == 0) {split($0,b,"."); ...
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2answers
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Printing lines from one file if part of them appears in another. Both files are millions of lines long

I have two files, let's call them 123.txt and 789.txt. 123.txt is 2.5M lines long, and 789.txt is 65M lines long. Is there any way to use grep or similar to keep any lines from 789.txt that contain ...
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3answers
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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 ...
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4answers
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Extract data from line and prepend to the line?

Ok, I have some data in the form: <a href="/praha/jaktovidi/_zprava/jak-to-vidi-rektor-richard-hindls-5-cervna--1220102"> <a ...
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2answers
220 views

Tell a regex expression to skip the beginning of a line before matching

If I had a string like 45mb ./aaaa/bbbb/cccc/dddd and I use a regex like [^\/]*\/ it will match 45mb ./aaaa/bbbb/cccc/ I only want it to match ./aaaa/bbbb/cccc/ but I can't figure out how to do ...
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4answers
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using simple regex quantifier expression in grep

Does anyone know why ls | xargs -n 1 basename | grep -E '[0-9]{1}' does not only show occurrences of a single digit between 0-9? For example if I have: touch 1 touch 22 touch 333 touch test_file ...
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1answer
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How to use GNU tools to extract and merge two substrings of the same string?

Suppose I get the following result after doing a grep "emailed" /home/John/logs/2013-07-10.171222-0400EDT.html:I have emailed Mark. Thanks I want to extract the date from this so that my output ...
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2answers
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How to grep recursively in order of last modified time?

grep -r does a recursive search in all files in a particular directory. However, if I want these files to be read by grep in the order of their last modified time, how do I do that?
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1answer
291 views

grep curly-bracketed entries from text file

I have a file with many curly bracketed words, ex. {test1}, {test2} - how would I grep for these words and output a distinct list of them? output example: {test1} {test2} I've tried this which ...
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3answers
207 views

Cat 2 files and avoid duplication of lines

I have the file1 with the following content {"name":"clio5", "value":"13"} {"name":"citroen_c4", "value":"23"} {"name":"citroen_c3", "value":"12"} {"name":"golf4", "value":"16"} {"name":"golf3", ...
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3answers
158 views

grep for strings that were found in a previous statement

I'm trying to find out if an address definition is used inside of fortigate configuration file. I extracted the section out of the configuration file, that contains the addresses. In that section the ...
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1answer
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Reading grep patterns from a file

I have a couple of big text files and in the file UNIQS.txt I have a list of strings to grep from another file. The code I use is grep -f UNIQS.txt EEP_VSL.uniqs.sam > UNIQ_templates.sam which ...
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2answers
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Is grep part of coreutils? (If not, why?)

I have read in a few websites that grep comes with coreutils (e.g. https://wiki.archlinux.org/index.php/Core_Utilities) However, after building them, I noticed that grep is missing. I wonder if I ...
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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 ...
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5answers
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How to grep for text in a file and display the paragraph that has the text?

Below is the text in the file: Pseudo name=Apple Code=42B state=fault Pseudo name=Prance Code=43B state=good I need to grep for "42B" and get the output from the above text like: Pseudo ...
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1answer
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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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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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3answers
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When grepping a file, grep is returning true instead of the lines, why?

I am running a grep on a file that is about 13G in size. It is returning Binary file file.xml matches I was not expecting this, I thought it would return each line with my string so that I could ...
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1answer
99 views

Is there a grep switch that reads a file for filter terms?

Assuming file a.txt has: 1a 2b 3c 4d so grep "1" a.txt would return: 1a and grep "3" a.txt would return: 3c what if i want to put a criteria file named crit.txt with the following ...
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What is the difference between “*.pl” and *.pl in grep? Why does quoting change the result?

What is the difference between: grep "string" . -r --include *.pl and grep "string" . -r --include "*.pl" The latter includes files in subdirectoried while the former not. Why?
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Grep and regex, Why does the following return only a specific portion?

Why in the following: echo this is a line. | grep -o -E "[a-z]+\." The result is line. and not this is a line.? There is no word boundary or any other restriction on the regex.
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Is -r mandatory for grep?

In a directory I have a file that contains the word string. When I do: grep "string" . no results are returned. But when I do grep -r "string" . the file is returned. Why is -r option needed? It does ...
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3answers
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How to find a space in a text. using grep?

How to grep one space in text ? cat a.txt| grep ' ' or cat a.txt| grep '\s '
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1answer
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Issue with real-time log inspecting piping tail, grep and cut

I have to inspect a growing log in real time, and I found an issue that makes me miss some lines (I can't understand exactly what lines) using tail -f or tailf, grep and cut. I use grep because I ...
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2answers
638 views

Add a suffix string to end of each line? [duplicate]

I have two files: file01: line1 line2 line3 file02: A B C And I want to get line1 A line2 B line3 C I could possibly write a Perl script but it is better if I don't need to. I have tried ...
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4answers
374 views

Use grep with or [duplicate]

How do I search in a textfile with grep for the occurrence of a word or another word? I want to filter the apache log file for all lines including "bot" or "spider" cat ...
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5answers
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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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6answers
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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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2answers
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“Ungrep” - which patterns aren't matched

I'm looking for a command or script to do the following - given: file1.txt: abcd efgh ijkl mnop file2.txt: 123abcd123 123efgh123 123mnop123 I want a command that does something like this: ...
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how to count total number of words in a file?

I am looking for a command to count number of all words in a file. For instance if a file is like this, today is a good day then it should print 5, since there are 5 words there.
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2answers
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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 ...
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2answers
107 views

Grep and sort several unsorted things in several lines (in one document)

I have a file with several unsorted things in one line which I want to put into a new file This is an example of part of the file I have: X1314448: SaMi|SM_g2554.t1 SaMi|SM_g5072.t1 Des|Des_g3808.t1 ...
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1answer
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What is the meaning of this test expression []? [duplicate]

I've seen someone use command: ps -ef | grep [h]ttpd and Output is: apache 25125 31006 0 21:54 ? 00:00:00 /usr/sbin/httpd apache 26869 31006 0 22:04 ? 00:00:00 ...
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1answer
70 views

How to get all Users and echo if they work or not?

How do I get a list of users(given from the command line) with grep and output if they are logged/work or not ?
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1answer
11k 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 ...
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1answer
303 views

How to Get FreeBSD Grep to recognize '-' option?

I am using FreeBSD grep, version 2.5.1, and want to be able to have grep read the pattern from stdin. Other versions of grep I have used allow for the specification of - to enable this feature. ...
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3answers
168 views

| Grep, Find which file the strings came from

I have a set of PDFs, and I am running strings * | grep message This returns the strings containing that method, is there anyway I can get grep to tell me which file it is from?