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

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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 ...
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1answer
561 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 ...
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1answer
117 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
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2answers
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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 ...
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1answer
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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 ...
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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?
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5answers
108 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 ...
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2answers
49 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 > ...
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7answers
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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 ...
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2answers
289 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?
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7answers
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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, ...
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2answers
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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 ...
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5answers
373 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 ...
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4answers
69 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 ...
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0answers
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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> ...
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1answer
39 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 ...
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1answer
4k 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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6answers
846 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?
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1answer
23 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 ; ...
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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, ...
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4answers
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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 ...
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1answer
75 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
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1answer
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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 ...
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6answers
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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 ...
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2answers
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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 ...
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0answers
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Get only files specified in egrep

I could to like ask how to get only the files that contains or match with this command [ "$(egrep -l 'GE.[100|120|140|159].' /home/test_dir/* xargs egrep -l 'EA.[NT|[HD|HS|QR].')" ]; My problem ...
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1answer
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command: ls /etc | sort | grep d* is yielding no results but ls /etc | sort | grep p* lists entire directory

I am playing around with piping and grep tonight. I know that grep uses regex and that * means 0 or more occurrences of the preceding character. So the way I understand it is that if I do the ...
6
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1answer
259 views

find words with all vowels in order from a file

I have a large dictionary file with 300,000+ words in it and I'm trying to find all words with the vowels aeiou in that order and have only exactly 5 vowels. My current attempt does not seem to be ...
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2answers
55 views

Extract certain column from CSV files [closed]

I have a directory with a group of CSV files. All files have the same column headers. I need to extract values in a certain column from all files. The common part in files names is ...
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4answers
207 views

How to replace m part of Lines with n part of Lines?

I have a file "test" like this: RewiteEngine On RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.7$ [NC] RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.8$ [NC] RewriteCond %{REMOTE_ADDR} ...
0
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1answer
51 views

Print lines if pattern is not matched

Print lines of File 1 only if they don't contain patterns specified in File 2 Exemple: $ cat File_1 L1 pattern1 L2 pattern pattern2 L3 pattern3 pattern L4 pattern4 $ cat File_2 ...
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2answers
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How do you get fgrep to find the literal “--help”?

fgrep --help | fgrep "--help" returns just the whole fgrep --help, how do I return just the lines that have the literal "--help" in them? The quotes don't do anything, nor does \-\-help.
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What are the exact differences between awk and cut with grep? [closed]

We know that we can get the second column of the line we want from a file using these two techniques: awk '/WORD/ { print $2 }' filename or grep WORD filename| cut -f 2 -d ' ' My questions are: ...
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2answers
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Will grep go faster with line breaks?

I have some big files that I have changed into "standardized form", removing line breaks. I want to speed up greps on those files. I know that you can optimize grep by doing grep 'partofpattern' | ...
2
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1answer
26 views

Grep patterns in selected lines

How to keep rows containing pattern 1 only if the next line contains pattern 2 and starts with pattern 3 ? Exemple: keep line starting with an A only if the next line starts with a B and contains ...
3
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1answer
46 views

How to export data in the terminal to a file (e.g. csv file)

I am a complete beginner in using Linux and I would like to know how to export a bunch of data in the command line to a csv or spreadsheet file (or even text would work). Right now I am simply using ...
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2answers
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How to use grep to find all instances of one .txt file in another?

How would I use grep to compare if any line from one .txt document occurred in another? Further how would I use grep to find out the opposite? Would it be grep -v?
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4answers
57 views

Matching string with a fixed number of characters using grep

I am trying to find all 6 letter words using grep. I currently have this: grep "^.\{6\}$" myfile.txt However, I am finding that I am also getting results such as: étuis, étude. I suspect it has ...
4
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1answer
35 views

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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0answers
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agrep with directionally biased penalties

I am using tre-agrep, an implementation of agrep, to perform approximate pattern matching. This utility searches for matches based on Levenshtein distance, and the user can configure the penalty ...
0
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1answer
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For a given directory, how do I concatenate the tail end of recently modified files to a new file?

In case there's a better solution to the problem, my goal is to be able to quickly analyze ALL recent apache activity in /usr/local/apache/domlogs. The usefulness of this is when the server load is ...
8
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3answers
14k views

How do I count the number of occurrences of a word in a text file with the command line?

I have a large JSON file that is on one line, and I want to use the command line to be able to count the number of occurrences of a word in the file. How can I do that?
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2answers
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How to list similar lines?

The delimiters could be: " "; "_" INPUT: foo#foo_ehh113#The password of user 111 will expire within the next seven d foo#foo_ehh204#The password of user 111 will expire within the next seven d ...
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11answers
7k views

How can I “cat” a file and remove commented lines?

I'd like to know if there is a way that I could cat file like php.ini and remove all lines starting with ; For example, if the file contained this: ; - Show all errors, except for notices ; ...
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3answers
65 views

grep substring between quotes

Let's say I have a string like this: title="2010-09-11 11:22:45Z" How can I grep the date itself and disregard the quotes/title/Z? The file can contain more strings like: randomstring ...
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4answers
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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?
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2answers
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Why is `tac file | grep foo' (piping) faster than `grep foo < <(tac file)' (process substitution)?

This question was motivated by "Reverse grepping", about grepping a huge file from bottom up. @chaos said: tac file | grep whatever Or a bit more effective: grep whatever < <(tac file) ...
7
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4answers
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Find the exact string with grep

by way of example, I've a big text file with many email address, using bash I need search/verify that an email exists (or no). Should be use (only) the "anchors"? grep '^user1@example.com' text_file ...
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1answer
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how do I recursivley grep (or otherwise search for) hex strings

Long and short I'm trying to track down some files left by evil scum on a server. fgrep -r "STRING" /path/here has been working well for finding general stuff. However, how do I search for hex ...
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3answers
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List all the html tags in a file

I want to know if there is a way to list all the html tags in a file. Lets say I have a file file.html <html> <head> <title>Test</title> </head> <body> This is a ...