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

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1
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4answers
67 views

“head” only printing one line?

I've got a CSV file that's generated by saving as CSV from Excel. If I do "head" (or indeed "grep" or anything else) it only prints the first line: head -n 10 messy.csv 10,15,11,21 But if I open ...
2
votes
3answers
36 views

Split command and arguments, and put into variable in a bash script

I have a script that repeats the same (very long) grep command many times. I want to make the script more readable by cutting the line length, so I tried to put parts of the command into variables. ...
0
votes
2answers
38 views

parsing out duplicate barcodes in a separate line

I've got the following data I need to parse out the duplicates from column1 into a separate file, For example, 21288003132541:cr 21288003267289:fr 21288003758683:ph 21288003758683:tag ...
-2
votes
1answer
26 views

exclude names without a comma

How do I exclude names from my list that have no comma and output them to a file? Should I use grep? Example: Charlie Chapman William, Henry Gary, Stevens Mark Twain Harry Potter Smithy, John Mon
2
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4answers
61 views

Print alternating lines with conditional

Still struggling with messy logfiles. What I want is to find lines that first matching string X and then string Y. I then want to print them together. The problem is that, sometimes there is X, but no ...
7
votes
4answers
277 views

How to grep-inverse-match and exclude “before” and “after” lines

Consider a text file with the following entries: aaa bbb ccc ddd eee fff ggg hhh iii Given a pattern (e.g. fff), I would like to grep the file above to get in the output: all_lines except ...
1
vote
1answer
16 views

Filter screenlog with screen command

Pressing Ctrl+A, H, lets me log output of the screen command. However, the output file is too large. Is it possible to apply a grep-like filter so that I can control what gets logged? For example, I ...
4
votes
1answer
50 views

How can I repair a tar file where stderr got mixed with stdout?

I have a tar file that I'm trying to repair. The problem is that tar's stderr got mixed in with its stdout, so the file looks like this: % head android-1435613730.tar tar: removing leading '/' from ...
27
votes
4answers
34k views

How to search text throughout entire file system?

Assuming that the grep tool should be used, I'd like to search for the text string "800x600" throughout the entire file system. I tried: grep -r 800x600 / but it doesn't work. What I believe my ...
3
votes
2answers
53 views

How do I filter stdout of a program through grep while still controlling the program?

I'm trying to filter the output of the mpv media player, removing a particular line, but when I do so I am unable to control mpv with the keyboard. Here is the command: mpv FILE | grep -v 'Error ...
2
votes
3answers
99 views

Split binary data of fixed byte offset by byte position?

I have binary data which I review by xxd -ps in hex format. I notice that the byte distance is 48300 (=805*60) bytes between two headers where the separator is fafafafa. There is the beginning of ...
-1
votes
1answer
43 views

To sed if with and without conditions correct

I know that I may have the C package #include <stdint.h> in the first 1-30 lines. I would like to add it to lines where no previously if the file contains the word LARGE_INTEGER by GNU tools. ...
1
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2answers
54 views

Search for a multiple patterns in specific column in fixed length file and output entire line

I need a command in Unix to look for a pattern in specific columns in a fixed length file and output the entire line to a different file. Example File1 2345abcdef450022677 1234sdfght350022677 ...
4
votes
6answers
172 views

Append something to each list in a file

I have a file, lists.txt, that looks like this: // stuff at beginning of file var list1 = new Array(); i = 0; list1[i++] = 'a'; list1[i++] = 'b'; ... list1[i++] = 'z'; var list2 = new Array(); i = ...
9
votes
5answers
523 views

How can I count the number of lines in a file after a grep match?

I am trying to count the number of lines after a problematic row in a csv file. I am aware I can use the grep -a # syntax to output # number of lines after a match has been found. I'm only interested ...
2
votes
1answer
18 views

Extract values from block of data

I have the below block of data. Heap after GC invocations=31 (full 3): par new generation total 131008K, used 0K [0x00000000eac00000, 0x00000000f2c00000, 0x00000000f2c00000) eden space ...
1
vote
2answers
53 views

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 ...
0
votes
1answer
2k 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
votes
1answer
67 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 ...
0
votes
1answer
40 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
votes
1answer
642 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 ...
3
votes
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
vote
1answer
33 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]} ...
1
vote
1answer
33 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 ...
0
votes
2answers
44 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
votes
3answers
27 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 | ...
1
vote
4answers
46 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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votes
1answer
40 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 ...
21
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11answers
23k 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
votes
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
votes
3answers
38 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 ...
0
votes
0answers
10 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 ...
1
vote
2answers
42 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. $ ...
6
votes
3answers
1k 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
votes
4answers
74 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
votes
1answer
24 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
votes
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
votes
3answers
357 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 ...
1
vote
1answer
34 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
vote
4answers
267 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 ...
4
votes
2answers
164 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 ...
1
vote
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
votes
8answers
452 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
vote
1answer
30 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
vote
2answers
86 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 ...
2
votes
2answers
54 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 ...
14
votes
4answers
24k views

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 ...
3
votes
1answer
45 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
vote
1answer
48 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 ...
12
votes
10answers
15k 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 ...