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

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3
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2answers
109 views

What does “if echo $line | grep -F = &>/dev/null” do?

I'm not sure what the following line does in a bash script: if echo $line | grep -F = &>/dev/null then ... I know &>/dev/null is short for >/dev/null 2>&1, I'm not sure, ...
0
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2answers
229 views

Grep / awk on multiple files to single output

I have several txt-files containing data, where i use grep to search for a current string of text, and use awk to filter out the variable i need. The string is repeated through the file, so i ...
0
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4answers
272 views

grep all the lines in a file and write line to a file from the pattern matching point

For example, a temp.txt file contains information like below: adsf on line jhkjhvjdbvjvbvbdjkvn qerwtt on line fdgdgdgdd qwqertg on line safffasffaf wrt on line adaddsd I want to grep for ...
-1
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2answers
57 views

piping with grep

I want to search "C" in the grades column inside the file "input.csv": roll,name,total,rank,grade 001,A B,78,23,C 003,F YZ,100,1,* and what I'm trying is: cut -d"," -f4 input.csv | grep "C" ...
0
votes
1answer
70 views

live tail (tail -f) of file being grepped

i can do tail -f -n20 <file> to see the last 20 lines of the file, live. If i want to grep something, tail -f <file> | grep <pattern>, it will still be live, but will only grep ...
1
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2answers
34 views

Compare 2nd column of the 1st file and 1st column of the 2nd file and print the matched records of the 1st file

I have two files large files: f1.txt: 5020118359 |13ZJ24001218 |20141224|R 5020120475 |13ZJ38000813 |20141204|R 5020127431 |13ZJ38001569 ...
0
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1answer
54 views

grep for numbers over 10

I'm looking through a file for specific kernels. I want everything from 3.8. to 3.17. egrep 3.[8-17] is kind of the thing I want but that obviously doesn't work. How do I grep using the example ...
1
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5answers
271 views

To remove extra space from line using shell command

This is my file, TLRUIDA CBdms Status DP 6/1/1 DC 6/1/5 0 Y TLRUIDA CBdms Status DP 6/2/1 DC 6/2/5 0 Y TLRUIDA CBdms Status ...
3
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2answers
221 views

How to grep a log file from specific date to end of file?

I am looking to grep an Apache access_log file from a specific date/time to the end of the file, so for example I want to grep from the first match of the following string to the end of the file: 19/...
3
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1answer
15 views

Searching for specific user group membership with an exact match

A user has multiple group memberships that contain spaces. Example: mydomain\staff mydomain\staff admin mydomain\staff super User groups can be returned using: id -Gn username | grep -i -o '\...
1
vote
1answer
52 views

Estimate time spent on Git project with grep

Consider a Git log: commit 4d6b30238fbfc972ea4505cadf43abd316506d9e Author: Dotan Cohen <dotancohen@foobar.com> Date: Mon Jan 11 22:41:21 2016 +0200 Final foobar version commit ...
0
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1answer
45 views

How to select lines in a file that contain a number from a list of numbers

I have a text file, file.dat, with a number of columns separated by a space. There are some numbers in the second column. I have another text file, select.dat with a list of numbers. I'd like to ...
2
votes
2answers
104 views

How to append string with dash?

I am trying to append create a string that will be evaluated in the middle of a grep line. It is to find possible occurrences of different usernames within a certain file. However, I do not know how ...
1
vote
1answer
59 views

cshell alias: How to use nested single quotes(') in in cshell alias

I am trying below alias in cshell: alias sll 'ls -l \!* | grep -oE '[^ ]+$' | paste -s | xargs ls -l' For this CSH says, Illegal variable name. If I use \$, alias will be set without any error. ...
2
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2answers
62 views

Autocomplete from grep output

How might I more easily use a filename found by grep as an argument to vim: $ grep -r foo * lib/beatles/john.c lib/pantera/phil.c lib/pinkfloyd/roger.c lib/pinkfloyd/richard.c lib/whitestripes/...
1
vote
1answer
48 views

grep content between two starting bracket

Below is file output that I want to access [1] RsyncCommand: 0 Number of files: 18 Number of files transferred: 0 Total file size: 24.01M bytes Total transferred file size: 0 bytes Literal data: 0 ...
0
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0answers
17 views

How to take lines containing a particular string tag from a text file and add then to another text file?

I have a large text file with some data that I need and a lot of data that I don't need. The data that I need has a string tag at the beginning of the line followed by a numerical value which I need. ...
4
votes
6answers
360 views

Take grep value and output the count and the value together

I am trying to make a bash script that greps value and output the count and the value together Something like this grep -c 'Thenis' example.txt > example.lst But in that list file not only to ...
5
votes
1answer
76 views

Behavior of grep -o on OSX

On Linux, when I do echo foo | grep -o '^.' to get the first character, it prints f as expected. (I know, | cut -c1 would probably be faster.) But on OSX, doing the same results in 3 matches (3 lines)...
4
votes
1answer
179 views

grep of top output yields funny characters upon redirection to file

I am running CentOS 6 and I am trying to grep the output of top and redirect it to a file. I.e. top -u user1 -n 1 | /bin/grep somecommand &> scratch.txt The output of vim scratch.txt is ^...
0
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2answers
224 views

Parsing HTTP response with shell

I want to parse below HTTP response but I cannot figure out how to grep the values separately using a single curl request. I need these two output. 1. status_code - (Array of HTTP status codes) 2. ...
1
vote
3answers
117 views

grep a awk string from a file and write to the other part of string file

My file, aaa,has 5 lines. 01_AAA-11-ID22 02_BBB-33-ID44 03_CCC-55-ID66 . . I tried to grep anything after underline from a file bigfile.txt for i in $(cat aaa) do A= $(awk -F '_' '{print $1}' $i) ...
0
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1answer
212 views

Fetching logs from log file using grep

I am trying to fetch logs from log file using grep command and format of log file is as follows: [1/10/16 23:55:33:018 PST] 00000057 ServerObj E SECJ0373E: Exception message at com.own.ws.wim.util....
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votes
1answer
41 views

cut command behaving differently when its output is “ * ” [duplicate]

I am trying to create a shell script, below is a part of which where i am trying to extract some value from a record in a file: tgt_val=`cat $file_name | grep "$string_name" | cut -d"|" -f$column_no` ...
2
votes
2answers
64 views

Selective extraction of data

I have the following block of data in a txt file : Informatica(r) PMCMD, version [9.5.1 HotFix4], build [313.0217], SOLARIS 64-bit Copyright (c) Informatica Corporation 1994 - 2014 All Rights ...
0
votes
1answer
102 views

Using sed instead of grep to output only matching part of line

I am writing simple bash script (actually learning how to do it ) and i want this function to use just echo and sed and return exactly the same output. I found solutions with sed, they worked in ...
10
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3answers
332 views

How to extend bash aliases

How to create an alias that actually extends another alias of the same name in Bash? Why: I used to have GREP_OPTIONS set on .bashrc to something like this: GREP_OPTIONS="-I --exclude=\*~" I also ...
2
votes
1answer
122 views

Colored Output from Bash Script

I'm running grep inside a bash script. If I run the grep command directly, I see colored output of the file name and search string: grep -i username /tmp/sess_* If I put that command in a bash ...
0
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0answers
35 views

Reboot on grep in /sys directory

I just run the following command (on a Android in VirtualBox): grep -Hirn 'VirtualBox' /sys/* and the system rebooted. I wonder why this is the case, any suggestions?
1
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2answers
81 views

Complex sed Command with AND/OR/NOT

I have a bunch of php files which have many select commands. In each query i want to insert a coloumn variable admin_id = '$admin_id' i.e. if the query is select * from users where abc='xyz' and qwe='...
1
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3answers
470 views

regex matching and substring extraction

I have these files, manually created by many different people are coming in. Formatting, although following a certain rule, is not uniform. think of these three lines below "...
0
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1answer
33 views

Pattern highlighting command [duplicate]

Folks, I want to know if there exists a command that just highlight some portions of the input text, rather than filtering it like grep does. To give an example, suppose the following input text: ...
1
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0answers
39 views

Can I clear an env var during bash completion?

I use bash completion from https://bash-completion.alioth.debian.org/ and some vendor supplied scripts too (eg. https://github.com/git/git/blob/master/contrib/completion/git-completion.bash) I also ...
1
vote
3answers
118 views

remove files based upon diff of two text files

I have created two .txt files that look like: 5fba026dcf271c6fa174b9fc2fc1fefadf1370f9 ./.changeFiles/change/addImage1.change bb352fba5807f4d03ea11abb00e411b00ce38673 ./.changeFiles/change/...
1
vote
2answers
44 views

Return line conditonally on next line

I am trying to return a list of IP Addresses for computers that have a windows OS (for my security course). The output is in this format Nmap scan report for 192.168.xx.xxx Host is up (0.066s ...
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0answers
51 views

How to extract weather data from a html doc using linux string manipulation

I need to extract these info from this weather forecast site, but I don't know how much about string manipulation in linux: acm_RecentLocationsCarousel.push({name:"Irvine, CA", daypart:'day', ...
1
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4answers
193 views

How to show only hidden directories, and then find hidden files seperately

I'm trying to list all the hidden files in a directory, but not other directories, and I am trying to do this using only ls and grep ls -a | egrep "^\." This is what I have so far, but the problem ...
1
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4answers
69 views

bash extract a substring from “1.2.3-SNAPSHOT”

How can I substring a 1.2.3 from a 1.2.3-SNAPSHOT from bash? I tried echo '1.2.3-SNAPSHOT' | grep -o "^.*(?=(\-SNAPSHOT$))" but it didn't work Ideally I'd like a command to return 1.2.3 in both ...
1
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1answer
115 views

grep -f failing on a file edited in Windows

I just want to share a problem I had this morning using grep -f to obtain the patterns to match from a text file. Symptom $ echo 'sandbox/test/script.py' | grep -G '^sandbox/' sandbox/test/script.py ...
1
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2answers
443 views

Prefix and suffix strings to each output line from command

I have ran into a problem trying to write a Bash script. When grep outputs, it returns (usually) many lines. I would like to prefix and suffix a string to each of these output lines. I would also ...
2
votes
5answers
203 views

How to make grep return value without comma [duplicate]

I want to extract a value from a json file so that I can process it and I try that using grep '"USDEUR" currs.json' | cut -d ':' -f 2 but it returns 0.918695, and the json file looks like this: { "...
1
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1answer
60 views

Unix awk decimal export in pipe

I'm struggling to adapt a script, which loops through a large number of individual files (subj_id), and prints out the value of $4 in a specified line. Text file contains lines # Measure Brain, ICV, ...
4
votes
2answers
58 views

Invert matching lines, NUL-separated

I’m writing something that deals with file matches, and I need an inversion operation. I have a list of files (e.g. from find . -type f -print0 | sort -z >lst), and a list of matches (e.g. from ...
5
votes
2answers
71 views

Scrabble helper in bash

I'm trying to make a scrabble helper in bash, which when given a list of characters, finds all the words in the /usr/share/dict/words file. For example, when given the letters a,c,r,t The word cart ...
0
votes
2answers
89 views

Parameter expansion in grep

To retrieve strings of the following pattern from a text file populated with multiple entries: entry=G_1234 entry=G_5678 entry=G_2345 The following grep statement doesn't provide any result grep -...
0
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3answers
516 views

sudo iwlist wlan0 scan | grep ESSID > essid.txt (How do I export without the word ESSID in txt file)

So my goal is to answer my other question I am working on. Which is Connect to Open Wifi. Currently I am getting close, as I know there is only one Wifi connection, I would like to export the results ...
5
votes
3answers
249 views

egrep regular expression - same word in the beginning and end

I want to find all the lines that have the same word in the beginning and in the end of the line. For example: goodword fgdlakj 3t sfkl 43lk fkl goodword bad sfa;lk3t dgk;gs 34;kl ...
1
vote
3answers
54 views

script not running as expected when scheduled as a cronjob

I'm trying to write a script that will identify corrupt jpg images using imagemagicks identify command. The script will run the command, grep the output for the word "Corrupt", move it to a corrupt ...
0
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4answers
75 views

Why isnt this simple grep/sed script working [closed]

I have a variable with, among others, a line that looks like this iBMC=277 I'm trying to match that like this: BMC="$(echo "$allnow" | grep iBMC=[0-9] | sed 's/iBMC=//g')" This makes BMC empty. ...
1
vote
1answer
31 views

How do I get grep to search for ebuilds with specific strings and produce an output containing only the ebuild's location?

I have been trying to create a Bash script function that can be used to search for and open ebuilds with desired strings in Atom (the text editor). This is my current Bash script function (stored in ~/...