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

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6
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3answers
204 views

How to get multiple lines out of a file by a regex?

I am trying to read part of an XML/SGML file (they are not necessarily well formed or in a predictable syntax, so a regex would be safer than a proper parser. In addition I would like to be able to do ...
4
votes
5answers
185 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 ...
5
votes
3answers
207 views

With grep, how can I match a pattern and invert match another pattern?

With grep, I want to select all lines that match a pattern, and that don't match another pattern. I want to be able to use a single invocation of grep so that I can use the --after-context option (or ...
1
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2answers
123 views

mv complains about standard input in a pipeline that filters file name with grep

I'm trying to move several .avi files that have spaces in from a CD to my home folder. I've already know how to get rid of the spaces: find /media/mathscd/ | grep -L -r "*.avi" | for file in *; do ...
4
votes
2answers
674 views

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 ...
1
vote
2answers
155 views

Show only part of the line found by grep (but not the part that matches the pattern)

In ifcfg-eth0, I managed to grep "DEVICE=eth0" by using grep "DEVICE=" ifcfg-eth0 But how can I grep pattern to show only "eth0"?
1
vote
2answers
112 views

Using grep to search a file

Re : grep command. I have to search a file for the names of all the students in the school's Linux system. I am able to do this and return about 665 names. (First string of /etc/passwd file). ...
3
votes
1answer
235 views

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 ...
2
votes
1answer
316 views

Search and Filter Text on large log files

I use the tail, head and grep commands to search log files. Most of the time the combination of these 3 commands, in addition to using pipe, gets the job done. However, I have this one log that many ...
3
votes
2answers
167 views

grep entire filesystem blocks on devices

Command grep -rHinF --colour=always -e "aa:aa:aa:aa" / Output grep: /dev/geom.ctl: Operation not supported by device grep: /dev/devctl: Device busy It seems that grep can not proceed because it ...
1
vote
1answer
164 views

How to use awk or sed to convert csv diffs into more readable format

Can anyone give me the example of how to use awk or sed (not sure which one, as I haven't use either of these much, as I have mostly been using grep and cut to work with csv data) to convert ...
2
votes
3answers
397 views

Printing match groups with grep

I have the following grep: grep -Po 'href="(http://.*)">Transcript.* - ([0-9]*)\. (.*)</a>' I would like to print out the match groups. Is there a way to do this without Perl/Python? I ...
4
votes
3answers
187 views

Using a perl compatible regex with GNU grep -P

I'm using this regex (?<=\[')[^,]* on a file containing the following line disk = ['OVS/sdasd/asdasd/asdasd/something.img, w'] I want that to return OVS/sdasd/asdasd/asdasd/something.img How do I ...
12
votes
8answers
809 views

How to perform a multi line grep

How would you perform a grep for text that appears on two lines? For example: pbsnodes is a command I use that returns the utilization of a linux cluster root$ pbsnodes node1 state = free ...
1
vote
1answer
101 views

Retrieving two matches from repeated pattern

How can I retrieve matches from two repeated patterns: mappedname & its value in the text below?. MapName:abc someDiffName=someDiffValue x=3 y=6 NeedyMappedName=NeedyMappedValue . . Flag=true ...
6
votes
5answers
222 views

Get filesystem name and usage with `df -h`

df -h | grep test | sed -e 's/*%.^ //g;s/.*[ ^I]//' Output: /test /test/drv0 /test/drv1 df -h | grep test | cut -d '%' -f1 | sed -e 's/*%.^ //g;s/.*[ ^I]//' Output: 10 20 15 I want to ...
3
votes
1answer
472 views

Get all regex matches between two patterns and print them to file

I've got a file with a bunch of long lines. I'd like to grab every group between two patterns and print them to a new file, one match per line. I could manage to do this with Python, but I'd prefer ...
6
votes
3answers
98 views

generate links of pages with incrementing variable

consider the links http://unix.stackexchange.com/questions/tagged/linux?page=2&sort=newest&pagesize=15 ...
0
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2answers
123 views

grep + operator

According to the grep manual: * The preceding item will be matched zero or more times. + The preceding item will be matched one or more times. Let's test it echo 'agb' | grep 'a.*b' # returns ...
2
votes
4answers
136 views

AWK Search massive file and write to variable name

I want to pull data that I will need to reformat from a simulation file I am working with to prepare it as input for running other simulations. The target data is an optimized chemical z-matrix. The ...
2
votes
4answers
266 views

Zgrep stop after first match when arguments are passed from xargs

I'm using this command to find patterns in zip files (similar to the one) suggested here http://superuser.com/questions/144926/unix-grep-for-a-string-within-all-gzip-files-in-all-subdirectories find ...
2
votes
0answers
219 views

exit code of grep in trap where the script is launched by upstart service

recently I encountered a problem in ubuntu upstart and trap in bash shell. I use ubuntu 12.04 the upstart script(/etc/init/player.conf) is: start on (local-filesystems and runlevel [2345]) stop on ...
9
votes
2answers
614 views

Script to quickly test all keyboard keys

I need to check some notebooks for bad keyboard keys, and so I'd like to speed that up as much as possible. I found nothing for this specific task, so my idea is a script that reads the pressed keys ...
2
votes
2answers
114 views

regular expressions with grep

I have this command right here: grep -B10 -A10 '14:14:50 {"channels":["/alerts/6979/new"],"data":"New alerts for unit 6979"}' mygateway.log Rather than searching for 14:14:50 I would like the 50 to ...
3
votes
5answers
167 views

How to grep, then search and replace on the output?

I have some output from iconv, e.g. $ iconv -l | grep ISO | head -5 CSISO4UNITEDKINGDOM// CSISO10SWEDISH// CSISO11SWEDISHFORNAMES// CSISO14JISC6220RO// CSISO15ITALIAN// durrantm:~ How can I change ...
2
votes
1answer
76 views

How to grep including single quote in a file

I have this line from file.php: 'user' => '', What would be the appropriate command using grep to query the exact line?
3
votes
5answers
363 views

How can I concatenate a single column of output into a list?

I'm using: ls /proc | grep -v "^[0-9].*" to get a list of all the files and directories in /proc that don't begin with numbers. The output is a single column list, i.e.: acpi asound buddyinfo bus ...
19
votes
3answers
2k views

grep: memory exhausted

I was doing a very simple search: grep -R Milledgeville ~/Documents And after some time this error appeared: grep: memory exhausted How can I avoid this? I have 10GB of RAM on my system and few ...
1
vote
3answers
282 views

grep for an alphanumeric strings of any length with a colon on each side

How would you grep for an alphanumeric strings of 1 to 50 characters (ideally, any length would work too) with a colon on each side – a typical result would be all the lines containing the string ...
2
votes
2answers
79 views

selecting specific string in a field

I have this file: N104 F1810 N104 F3810 N104 F810 N104 F305 and a script to grep an input. Script: enter input read input cat file | grep $input when I input “810”, I get the ...
0
votes
2answers
98 views

Count lines with alphabet in linux

I have a file with a number of lines in a file filename. I want to count how many lines start with character 'a', with 'b' and so on in one go. What command i should execute.?
3
votes
2answers
223 views

grep filter all lines plus one before each hit

I want to parse some output so I exclude all lines that contain either foo or bar, as well as all lines immediately preceding those lines. For example: echo " 1 some line 2 line to exclude because ...
10
votes
5answers
963 views

Using grep or awk

To capture a particular pattern, awk and grep can be used. Why should we use one over the other. How does this work in the background? Which is faster and why? E.g If I had a log file and I wanted ...
2
votes
3answers
263 views

Command substitution in for loop not working

I want to keep all files not ending with .bat I tried for f in $(ls | egrep -v .bat); do echo $f; done and for f in $(eval ls | egrep -v .bat); do echo $f; done But both approaches yield the ...
2
votes
2answers
92 views

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 ...
2
votes
4answers
469 views

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 ...
0
votes
1answer
79 views

Problem with small bash script

I often run find in my code projects when I make a change somewhere and I have to find where it impacts other pieces of code, so I thought about writing a very small script to make this easier, call ...
1
vote
2answers
153 views

How can I combine grep with file and extra regex

I have a file of strings in each line. For example: AAAAA BBBBB CCCCC etc I want to check each string one by one whether it exists in a series of files in a specific directory. I ...
4
votes
4answers
866 views

How to grep for pipe |

How can I grep for line containing pipe character | or for character >: files content: |this is test where is > this is none now what I need using grep command is grep -iE "<some ...
3
votes
2answers
492 views

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 ...
3
votes
1answer
252 views

Speed up zgrep on a multi-core computer

I'm running zgrep on a computer with 16 CPUs, but it only takes one CPU to run the task. Can I speed it up, perhaps utilize all 16 cores? P.S The IO is just fine, I could just copy the gzipped file ...
1
vote
3answers
184 views

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 ...
2
votes
2answers
242 views

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 ...
2
votes
3answers
236 views

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) ...
1
vote
2answers
157 views

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 ...
1
vote
1answer
82 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 ...
0
votes
1answer
112 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 ...
4
votes
1answer
183 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 ...
2
votes
1answer
388 views

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 ...
-1
votes
1answer
526 views

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: ...