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

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2answers
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How do i search for certain sections of a file and then extract only relevant information within that section?

So I have a text file that is a server report and has about 1000 lines of information in it. I'm trying to write a script that can search the report for only certain pieces of information I'm looking ...
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1answer
3k views

grep: match pattern on a particular position

I need to match a pattern with grep, only if it starts at position 16. Let's suppose I want to match the string ' pattern' (starting with space). The following should match bla bla bla bla pattern ...
2
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1answer
73 views

Match a number range with grep

I need to find all processes that have in their names a number between 100 and 200 inclusive. I tried ps -ef | grep xclock -bw '[1-2][0-9][0-9]' but that includes 299. How to suppress it and ...
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1answer
50 views

Delete email addresses in .csv that are listed in a .txt file

I run the following command to keep email addresses listed in emails.txt grep -wFf emails.txt file.csv > newfile.csv But how would I change this command to remove addresses from file.csv that ...
5
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1answer
680 views

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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8answers
3k views

grepping dotfiles with -R correctly?

From time to time I need to find a culprit in an unknown dotfile and instead of trying to figure out which package is to be blamed (e.g. xfce4 or thunar?) and what is their naming convention (.app vs ...
1
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1answer
35 views

Obtaining unique lines with matching strings [duplicate]

I have a JSON like text file of records with duplicate ids that look like: {"ID":"93" , "ST":[42,77,51]} {"ID":"21" , "ST":[43,4]} {"ID":"94" , "ST":[65,11,4]} {"ID":"93" , "ST":[42,77,51,29,63]} ...
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1answer
37 views

Is my understanding correct about egrep -if file1 file2?

I am using KSH, Solaris 5.10. Suppose file1 contains a list of fruits and file2 contains list of fruits & nuts. My understanding about the following command egrep -if file1 file2 is that it ...
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2answers
49 views

Grep for regex in basename but return wholename

So say I have a list of files in a text file: ... /foo/barfoo /bar/foo/foobar /foobar/bar/foo ... I have a script that will search through this text file and, much like the locate command, I want ...
4
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3answers
36 views

Timing of ps piped to grep

So, this isn't a problem as such, just something I'm curious about. I'm using Linux Mint MATE which is branched off Debian. If I do: ps afx | grep abcdefg I get: 16599 pts/3 S+ 0:00 | ...
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4answers
55 views

Find text in a file and copy it to another file

Is there any command in Linux to find text in a file and if found then copy it in another file? Using sed -i we can find text but how to copy whole line in another file?
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1answer
44 views

How to get more than 20 lines of output with grep when searching for a string with spaces [closed]

I am currently using grep like this: grep search_string search_file > output_file Here is an example: grep "ich arbeite" deu.txt > out.txt When used in this way, I only get the last 20 ...
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11answers
24k views

How can I grep in PDF files?

Is there a way to search pdf files using the power of grep, without converting to text first in Ubuntu?
5
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5answers
2k views

Why does grep not work with redirection?

Using the top command with redirection works fine: top > top.log Now I want to use grep to filter a certain line: top | grep "my_program" > top.log But the log file will remain empty. But ...
2
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3answers
39 views

grep .* returns results from .bash_history and complains about

I'm new to Linux and so far I've been playing around with some utilities, specifically the grep utility. I decided to create a new file (aptly called 'newfile') with the following content: Lady of ...
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0answers
13 views

Postgres server start fails - netstat -ant|grep 5432 output explanation?

I'm working on a Ruby on Rails app. Hosting on Heroku with postgres. Tried running "heroku run rake db:migrate" as usual, but getting error "cannot connect,... check if something else is already ...
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2answers
45 views

How to use multiline as group-separator in grep?

In grep you can use --group-separator to write something in between group matches. This comes handy to make it clear what blocks do we have, especially when using -C X option to get context lines. $ ...
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3answers
2k views

Suppress 'file truncated' messages when using tail

I'm tailing a log file using tail -f messages.log and this is part of the output: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce eget tellus sit amet odio porttitor rhoncus. Donec ...
2
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4answers
91 views

Change text in tag, but only tag is contained within a certain XML block

Using Git Bash, I'm trying to conditionally replace what's in the yrot tag in hundreds of files, but only if it belongs with a part name tag that pertains to wheel. // YES, change <part ...
2
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1answer
27 views

Unset all ENV variables matching _PROXY

I'm trying to unset all environment variables that match _PROXY: env | grep -i _proxy | column -t -s '=' | awk '{ print $1 }' | grep -iv 'no_proxy' | xargs -0 -I variable unset variable but it's ...
9
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4answers
7k views

How to perform grep on FTP?

I tried searching for similar command in ncftp (actually this is the only terminal ftp client I used) and I didn't find it. What's the way (if possible at all) to use grep command on remote server, ...
5
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3answers
365 views

Why does this one-liner fail to produce output? [duplicate]

The following produces nothing in bash: while true ; do upower -d ; sleep 1 ; done | grep percentage | uniq I've discovered that it doesn't matter what the last- or even the second to last- program ...
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1answer
58 views

“grep: memory exhausted” error on large partition

I was editing a text file with my notes on linux commands when I noticed a big chunk of it was missing (copy without paste, probably). The problem is that I already saved the document. (And this is a ...
1
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4answers
318 views

How to use regex to match a pattern which does not have a specific string at the end

How to use a posix bre or a posix ere regex to match a word which does not have bak at the end. I want to do a ls | egrep '<regex>' to find all files which DO NOT have bak at the end of ...
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2answers
187 views

how to extract parts of file into separate files in linux using awk or grep or sed commands

I have text file as shown below: Input file1.txt ....................... cha21 1 3 5 nar cha21 2 3 6 piy cha23 2 3 5 ram cha23 3 ...
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3answers
45 views

How to grep between words in a log?

I have a txt file with lines like below. Starting With: Parameters: {"raw_message"=>"MSH....... Ending With: </HL7Message>"} I'm wanting to grep and output to a file the words between ...
5
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8answers
638 views

How do I delete the first n lines and last line of a file using shell commands?

I have a file named Element_query containing the result of a query : SQL> select count (*) from element; [Output of the query which I want to keep in my file] SQL> spool off; I want to ...
1
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1answer
37 views

Trying to find all files in certain directory that are not referenced in other files

I have this project that has a images folder with images in them and I'm pretty sure some of them are not used. So I'd like to list all images that are not referenced in any other file. I'm not very ...
1
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2answers
93 views

How to filter content between specific keywords using grep?

I got a bunch of files, and I want to find out the content between two tags st and et. if I use grep "st.*et" files, I will get these two tags involved in the result. Such as st Hello world! et. But I ...
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2answers
56 views

is it possible to search for files that have a special Linux file attribute?

is it possible to search file in the linux OS that have particular file attribute as this: ---S--l--- ---S--l--- 1 root root 0 Mar 1004:25/opt/csTuner/iba/wys/tuer_lolk What is S in ...
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4answers
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Recursive grep vs find / -type f -exec grep {} \; Which is more efficient/faster?

Which is more efficient for finding which files in an entire filesystem contain a string: recursive grep or find with grep in an exec statement? I assume find would be more efficient because you can ...
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1answer
46 views

Grep ignores part of my pattern?

I have a nice bash/zenity script that I use to check/update a number of git repos and report the status of each like this - showing only one sample repo here: zenity --class=CheckGit --info ...
1
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1answer
52 views

why grep does not print the entire line? [duplicate]

When I enter ls command I get the below output. -$ ls aNode ANode bNode BNode cNode CNode DUMP file1 hello.txt TEST.txt -$ As seen, above output is one line which has filenames separeted ...
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10answers
16k views

How to print all lines after a match up to the end of the file?

Input file1 is: dog 123 4335 cat 13123 23424 deer 2131 213132 bear 2313 21313 I give the match the pattern from in other file ( like dog 123 4335 from file2). I match the pattern of the line ...
3
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4answers
223 views

Extract paragraph separated with *** using AWK

I have a file like below: blablabla blablabla *** thingsIwantToRead1 thingsIwantToRead2 thingsIwantToRead3 blablabla blablabla I want to extract the paragraph with thingsIwantToRead. When I had to ...
0
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2answers
56 views

Count frequency of specific numbers in a text file of scientific notations

Background I have a text file, named blood_conc.txt as shown: 0, 0, 0, 0, 0, 0, 0, 1.32006590271e-05, 1.990014992001e-05, 1.504668143682e-05, 2.176900659261e-06, 7.673488970859e-06, ...
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5answers
2k views

grep skip n lines of file and only search after

I have a huge log file and want to grep the first occurrence of a pattern, and then find another pattern right after this occurence. For example: 123 XXY 214 ABC 182 558 ABC 856 ABC In my example, ...
0
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2answers
22 views

Find a string between spaces

I was searching around the site and couldn't find a solution for the following, despite it's a simple thing. So let me share... If you know a better solution, please share I have the following log ...
29
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2answers
10k views

Why doesn't grep ignore binary files by default?

The manpage for grep describes the -I flag as follows: -I Ignore binary files. This option is equivalent to --binary-file=without-match option. It also says this about binary files: ...
0
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1answer
39 views

Copying files containing specific text preserving directory structure

Using the code in this answer, I can easily copy a file containing specific text from one folder to another. With the -r option I can also search inside directories recursively. The result is that ...
3
votes
6answers
175 views

grep with continuation lines

How can I grep/awk/sed a file looking for some pattern, and print the entire line (including continuation lines if the matched line ends with \? File foo.txt contains: something whatever thisXXX ...
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4answers
143 views

Using Grep -o or Sed/Awk to Grab Snippet from Middle of String

I am watching log traffic and see regular abuse of the various image search engines, Bing particularly. Example URL: ...
1
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2answers
38 views

searching for files with multiple strings (all inclusive, not one or the other ) and print line numbers

I want to search for 2 (or more) strings across the files of a certain directory and print the line numbers. The search results should include only those files where all the mentioned strings are ...
1
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3answers
2k views

Find files containing one string but not the other

I am in a folder with lots of .txt file, I would like to find all the files which contain stringA, but don't contain stringB (they are not necessarily in the same line). Does anyone know how to do ...
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2answers
2k views

How to do a grep on remote machine and print out the line which contains those words?

I have few logs files in my machineB under this directory /opt/ptd/Logs/ as shown below - My logs files are pretty big. david@machineB:/opt/ptd/Logs$ ls -lt -rw-r--r-- 1 david david 49651720 Oct 11 ...
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4answers
276 views

Match exact string using grep

I have a text file: deiauk 1611516 afsdf 765 minkra 18415151 asdsf 4152 linkra sfsfdsfs sdfss 4555 deiauk1 sdfsfdsfs 1561 51 deiauk2 115151 5454 4 deiauk 1611516 afsdf ddfgfgd luktol1 4545 4 9 luktol ...
2
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1answer
59 views

grep misreads pattern from variable

I have a problem with escaped pattern put in grep. My test file is: export_cc = ${dir}/aaa/bbb/ccc export_cc = ${dir}/aaa/bbb/eee export_cc = ${dir}/aaa/bbb/ddd export_cc = ${dir}/aaa/bbb/fff ...
12
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6answers
2k views

How to find files with 100% NUL characters in their contents?

What is the Linux command-line command that can identify such files? AFAIK the find command (or grep) can only match a specific string inside the text file. But I want to match whole contents, i.e. ...
25
votes
6answers
12k views

What makes grep consider a file to be binary?

I have some database dumps from a Windows system on my box. They are text files. I'm using cygwin to grep through them. These appear to be plain text files; I open them with text editors such as ...
12
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2answers
39k views

How can I assign the output of a command to a shell variable?

I want to assign the result of an expression to a variable and concatenate it with a string, then echo it. Here's what I've got: #!/bin/bash cd ~/Desktop; thefile= ls -t -U | grep -m 1 "Screen Shot"; ...