104 comment

1. you forget “\” so the command to search multiple string using grep as following
   grep ‘warning\|error\|critical’ /var/log/messages

   1. Thank you for this. I couldn’t figure out why it wasn’t working.

   2. And why did Vivek not correct this yet?

      Please.

   3. This is the first result in google. Please make this correction.

      1. The faq has been updated.

         Appreciate all feedback.

   4. thanks. it helped

2. It is good explain for grep

   but i want find out one particular string from another string. shall i use grep.

3. Thanks for the article. Is there a way to supply the words in a file? So in your example I could create a simple file containing:

   warning
   error
   critical

   I have over 200 words that I need to search – which is tiresome to put onto the command line.

   Thanks,

4. Use the -f FILE option to obtain patterns from FILE, one per line:
   grep -f words.txt /var/log/messages
   words.txt

   word1
   word2
   wordN

   1. Fantastic !! I had a scenario where in I had to pick up lines from a log file based on a word. Unfortunately I had 1000 such words and so it would have been difficult to find 1000 lines. But this solution really helped. Thanks.

      1. Hi,

         I have a requirement in which I would need to grep/find a line based on matching 3 different patterns. I know we can grep with -E multiple parameters seprated by pipe but this work Pipe (|) as OR condition. My requirement is I want to use AND condition. It should show line where it satisfy both the parameter.
         e.g. line in a file as —
         10-Aug-2010 Hello, this is a new example for unix.
         I need to show this line only when my grep command matches all 3 words
         this, new, unix How to right such grep command ?

         1. grep -n “$search1” . | grep -n “$search2” | grep -n “$search3”

            after the first grep only statements “search1” will come. this is filtered by the next grep creating and AND condition.

            this is a round about solution coming out the top of my mind. if i find a better solution i’ll post it.

            1. this dint work for me:(

               i used the cmd like grep -il SDI *.sql | grep -il Account *.sql | grep -il Customer *.sql
               My requirement is as follows :

               in the current folder, inside the files with extension .sql, i need to get the files hwich have SDI,Account and Costomer words in it.

               1. -l, –files-with-matches
                  Suppress normal output; instead print the name of each input file from which output would normally have been printed. The scanning
                  will stop on the first match.

                  did -l work for u??

5. How do you search for 2 strings on the same line?, but return the following line?

   1. grep ‘matching\|\(matching again\)’

6. how do we search for two words and return it when both words are exists in the line. just like AND operator.

7. just pipe two greps grep ‘hello’ file.txt | grep ‘world’

8. these all are not working

   try

   grep -E -e ‘warning|critical|error’ /var/log/messages in Linux
   /usr/xpg4/bin/grep -E -e ‘warning|critical|error’ /var/adm/messages

   1. The problem is that you need to ‘escape’ the or operator ‘|’ as shown above AND use the ‘i’ flag to be case insensitive:

      grep -i 'warning\|critical\|error'  /var/adm/messages

9. in solaris

   1. It doesn’t work in Solaris. Do anyone have any commands to find multiple string (say string1 and string2) in a file and retunrs the line as well?

      Thanks in advance.

10. How do I only return lines that have both words in the line

    grep -E “rob|bob” returns lines even if only one string is present.

    1. try
       echo “hi rob, where is bob?” | grep -E -o “rob|bob”

       it should return:
       rob
       bob

       1. use
          grep ‘rob’ | grep ‘bob’

    2. Use awk.

       $ echo “hi rob, where is bob” | awk '/rob/ && /bob/ {print $0}'

       1. Thanks, awk saved my day ;) as i understand it’s not just awk it’s regexp too?!

          so thanks again, the day was saved by the power puff girs… o0O0ops… awk and regexp!

          :)

11. I figured I should be more specific in my request.

    I have the following line;

    /usr/bin/dsmc archive -des=”DAILY” -archm=FS_DBARCH_DAILY “/brlog1/BIDW/redo/*”

    I want a grep command to return the line number of this line

    grep archive filename | grep -n redo doesn’t work because it returns the number of the line in the results from the first grep.

12. Thanks a lot.This saved my time. We have a delivery tomorrow.

13. @Nauman Ali,

    To search for two words, and to return only if both words exist in a file, use this command

    grep -Rl word1 *| xargs grep -l word2

    1. Thanks….that helped

14. Sasikala: THANK YOU!!!! That was very thoughtful of you to leave that for us, I needed it bad!!! :)

15. grep -Rl word1 *| xargs grep -l word2… how this work?

16. “grep -Rl word1 *| xargs grep -l word2… how this work?”

    It just doesn’t work.
    It will return the filename where exists at least one line where the two words are present. Which is no information at all.

17. @Robert Guest:
    Attach the ‘-n’ parameter to the first grep, not to the second:

    grep -n archive filename | grep redo

    that way the second grep will get a line that contains the line number.

18. Just try this one:

    grep word1 | grep word2

19. correction … :
    grep word1 filename | grep word2

    1. That won’t work if you need to check if word 1 and word2 are anywhere in the file, because the first grep returns the matching line, so the second grep would only match if both words were on the same line.

20. How do you search for the string below in a file using grep ?

    DeptId = ‘123459’

    Any help is appreciated.

    1. Wrap the entire search string in double quotes:

       grep  "DeptId = '123459'"  *

21. Hi,

    I want to search multiple string using grep and want to display only matching string.

    can any one pl guide me in this regards.
    eg.
    cat abc.txt |grep -e ‘ab’ -e ‘bc’ -e ‘cd’

    If ‘bc’ is there in the file abc.txt then output should display only ‘bc’ rather than displaying the entire line.

    Thanks & Regards,
    Omprakash

    Google for: grep multiple string and returning matching string

22. How to search multiple words in separate lines, inside a directory including sub-directory? Pls. give easy example.
    I tried $grep -r “word1” |grep -r “word2” /Folder/subfolder/ > search.log

23. try
    $grep -r “word1″ /Folder/subfolder/ | grep “word2″ > search.log

24. hi

    I have to grep exact line in file
    for eg : file name test.txt includes
    ram
    5) 1,2,3
    sohan
    5) 6,7,8

    so i want to grep ram and 5 so the output shud be
    ram
    1,2,3

    should not be
    ram
    1,2,3
    6,7,8

    1. First: grep is a single line utility. And because “5)” is on two lines, grep will find them, because it walks down the lines, and matches them to your rules, period.
       Second: what grep finds, that ‘entire’ line will be displayed. So it is not possible to cut the “5)” from the beginning of the line, and display the rest.
       If you want to find “ram” and after that the next “5)”, you need to use some utility that allows you to implement some logic. Like awk.
       However if you can ensure that “5)…” will be after the found line – like “ram” – then you can use the ‘after context’ feature of grep, whic displayes the matching lines PLUS some line after that.

       1. use this :

          grep ‘ram|5)’ test.txt | head -2 | tr -d ‘5)’

25. Hi,
    I need to list the files which contains the 3 strings
    <Tax
    <Source
    HEAD
    These all 3 strings may be in different lines.

    Thanks, Kumar

    1. @Kumar and others

       To search for multiple strings in a file try doing this :

       grep -il "String1" "PATH-OF-FILE" | xargs -I % grep -H "String2" % | xargs -I % grep -H "String3" %
       

       For eg:
       Let’s say I want to search for all those log4j.xml files which have the words CONSOLE and ASYNC in them .. then this is what I would do :

       find "/cygdrive/e/MyDocs/Downloads/work/OATS Domain related/" -iname "log4j*.xml" | xargs -I % grep -ilr "CONSOLE" "%" | xargs -I % grep -H "ASYNC" %
       

       Cheers!

26. hi.
    how to search a single line using grep command..
    for example a file having 100 lines in that 100 line only one error line is there.

    how do i retrive that single line using grep command.. i don’t know in which line in that error msg and like that error msg many of the lines in that file.. how do i find using ‘Grep’ command..

    1. do u have any keyword to identify the error message??
       for eg. if the keyword is ‘error:’

       then

       grep -rn “error:*”

       1. its
          grep -n “error:*” filename

          since its one file -r is not necessary.

27. echo year, month, Quarter,productTOT, RegionTOT,Per_type,Data_type,Bucket_noTOT,Curr_dateTOT

    from this output, i want only the string that has “TOT”

    so the output,

    productTOT, RegionTOT,Bucket_noTOT,Curr_dateTOT

    could anybody please help me???

28. Thanks a lot ,it works fine

29. hi, i want to grep the lines which has Eg:”uat” string in the but not “#” string in the line.. can anyone help me out in this????

30. /usr/xpg4/bin/grep -E ‘error|critical’ sample.txt

    this works for me..

31. Could you please help me regarding while connect putty Linux based logs like collect grep is working

    tail -f test_log | grep ‘\” 50[0234]‘ – working

    tail -f test_log | grep ‘\” 50[0234]‘ | grep “404″ – not working

    Any one help me on this regard? how to collect 1.500 to 504 2.404 alone.

    1. tail -f test_log | grep –line-buffered “blah” | grep –line-buffered “bluh”

32. Great info site.
    I have a need to search a file looking for dates and a string, For example:
    (Dec 2 13:25:27 name local5:warn|warning vmdaemon[180412]: #415 Moved volume tape_1 #0055 (12345678) (abc123 from online to offline.). I need to search for a date and the “online to offline” string together. Also, with grep is it possible to do a date range in the search as oppose to a single date?

33. It is very good for the student and all type of reader.

34. I also wanted to find all files that contained two separate words. The words could be anywhere in the file.

    One way that I found to do this is:
    grep -l word1 `grep -l word2 *`

    The backtick quotes execute what is inside the quotes and replace it with the results. -l returns file names only.

    More commonly I would also include -ir for case-ignorant recursive search:
    grep -irl word1 `grep -irl word2 *`

35. Here’s an interesting one that I have been wracking my brain on…

    I have some fairly large data files I need to search for certain conditions. Easy enough because I know the string I want to search for. However, the problem arises when someone duplicates the string in the field that I am searching for which expands the data criteria past my grep. here’s example:

    String = “000/C///” Field delimiter is pipe so I use: grep -i “|000/C///|” to match the condition. Now what I have found some people doing is using multiple strings in that field where only one exists. Is there a way to search for multiples of the same string without having to do a ton of greps in a row?

36. Trying to do things with the -A -B options –

    To display every line mentioning an astrological element:

    grep “earth|air|fire|water” astro.log

    How do I accomplish this new result with grep – I cannot figure out how to use the options -A and -B more than once within the same command.

    earth and the 2 lines following
    air – only the line containing air
    fire and the 6 lines following
    water and the 3 lines preceding

    This would result in a 15-line capture if the command works.

37. TRY…!!

    cat ASHOK.txt|grep -E word1|word2

    is working for me… :)

38. I am trying to pass the word/pattern from command line which I want to find in array but its not working. Say I want to find Jacob but its not returning anything.

    #! usr/bin/perl   use Fcntl; print "content-type: text/html nn";   print "Enter word : "; $word = ;   @myNames = ('Jacob', 'Michael', 'Joshua', 'Matthew', 'Alexander', 'Andrew'); @grepNames = grep(/$word/, @myNames);   foreach $Names(@grepNames) { print $Names; print "n"; }

    #! usr/bin/perl use Fcntl; print "content-type: text/html nn"; print "Enter word : "; $word = ; @myNames = ('Jacob', 'Michael', 'Joshua', 'Matthew', 'Alexander', 'Andrew'); @grepNames = grep(/$word/, @myNames); foreach $Names(@grepNames) { print $Names; print "n"; }

39. For me it works only if grep is set to use extended regular expressions with the -E flag

    grep -E One\|Two\|”Thirty five”

    Versions
    GNU bash, version 4.1.2(1)-release (x86_64-koji-linux-gnu)
    GNU grep 2.6.3

40. How do I used grep to fiind a vaue with a \\ contained within. For example. If I do a “cat /var/tmp/file | grep “NT Server\\Test” Nothing is returned.

    1. Try:

       cat /var/tmp/file | egrep  '[a-z]\\{2}[a-z]'

41. I have a file “nynorsk-utf-8.txt” in UTF-8 that is supposed to be in Nynorsk, one of the two official dialects of Norwegian. But it contains some “contamination” of Bokmal, the other official dialect. To try to identify the sections of Bokmal, I want to find all lines in nynorsk-utf-8.txt that contain any one of a set of 13 short words that are exclusive to Bokmal:

    ikke|jeg|fra|en|et|de|mye|hun|noen|se|selv|særlig|uke

    I’m on OS X, using egrep (GNU grep) 2.5.1
    I’ve tried the following:

    egrep -in “\” nynorsk-utf_8.txt > out.txt

    using \ to enforce word boundaries. Yet the output contains lines that do not contain any of these 13 words (as stand-alone words). I also tried

    egrep -inw ‘ikke|jeg|fra|en|et|de|mye|hun|noen|se|selv|særlig|uke’ nynorsk-utf_8.txt > outw.txt

    with the exact same results. Then I tried listing the 13 words, one per line, in a separate file ‘wordlist’, and launched

    grep -inw -f wordlist nynorsk-utf_8.txt > outf.txt

    again with the same results. E.g. each output file contains line 16

    16:– Dei fleste meiner at rota til den nye terrorismen er Ã¥ finne i ein tilnærma samfunnsstrukturell stillstand – ein tilstand som pregar bÃ¥de dei rike og fattige arabiske landa.

    that does not contain any of the 13 words (as a stand-alone word).

    Can anyone tell me what I’m doing wrong? or is there, perchance, a big in (e)grep?

42. Sorry–I’m new to this list, and my first example got corrupted. Let me try to mark it up to display correctly

    egrep -in “\<(ikke|jeg|fra|en|et|de|mye|hun|noen|se|selv|særlig|uke)\>” nynorsk-utf_8.txt > out.txt
    

    i.e. I used \< and \> as explicit word boundaries. The results were equivalent to launching

    egrep -inw “ikke|jeg|fra|en|et|de|mye|hun|noen|se|selv|særlig|uke” nynorsk-utf_8.txt > out.txt
    

43. Hi im facing a prob in matching multiple patterns.

    CODE:

    Variable=”abc* def*” # two patterns abc* and def* are stored in variable.

    I should use variable to find the matching lines. How can i achieve it.

    We use -f option if patterns are in a file. How to use when patterns are in a variable???

44. Hi All,

    I have two text files
    file one contains many words (single word per line) and file two contains many strings per line .
    Now I want to Grep every line from file2 which contains file1 word.
    Could any one help me out ?

    This is like extracting from file2 matches from file1 !!

    Very appreciated to the one who give solution here !

45. I want the code to Grep the row from file2 containing file1 strings !!!

    Eg :
    1.file2.txt
    Happy Diwali
    All is well
    One day
    2.file1.txt
    Happy
    One

    Now I want to Grep 1st and 3rd line from the file2.txt by file1.txt

    Appreciated answer !

46. !!!! Grep -f file1.txt file2.txt

    Works guys , cheers ;))

47. THanks nixCraft ,, it’s very useful

48. Best answer would be to use the egrep command to get this worked:-
    egrep ‘(str1|str2|str3)’

    For example:-
    bash-3.00$ cat triana
    Man is the most beautiful creator of god.
    Man is grate among all creators.
    Awsome one…

    Solution:-
    bash-3.00$ egrep ‘(grate|god)’ triana

    Man is the most beautiful creator of god.
    Man is grate among all creators.

49. Hello,
    I want to grep the pattern
    ‘
    ‘
    but i think grep command is not reading newline. Please give me any solution if any one have.

50. FILENAME=’trade.tmp’

    cat $FILENAME | while read line
    do
    #echo “$line”
    Keyword=`cut -d “)” -f 2 $line| cut -d “(” -f 2`
    Keyword_Count=`grep $KewKeyword $FILENAME`
    echo “$Keyword_Count,$Keyword” > trade1.log

    done

    HI ,

    In the above script i want to get the keyword and once i get the keyword I need to get the count of keyword.So i tried with the above script .it is showing the count first keyword only.Can anyone suggest me to resolve the problem.

    Thanks In advance

51. how do i search for a pattern /someword*/
    here someword can be A-Z or a-z or 0-9
    Any reply would be appreciated.

    1. grep “someword\*” filename
       This will do your work!!

52. Thanks for ur reply but I think i Did not tell my problem properly.

    My qustion is :-

    I need to search a pattern /someword*/ in a property file

    here someword can be any thing eg.A-Z or a-z or 0-9
    eg:-
    /goingTo/FollowingPattern*/=Yes
    /WhatASite/FloodsIn*/=No
    /dummyData/FinallyHere*/=QT

    here I have to search for patterns
    /FollowingPattern*/
    /FloodsIn*/
    /FinallyHere*/

    Hence someword is variable in property file.

    Any help is appreciated

    1. Don’t this work?

       $echo "/goingTo/FollowingPattern*/=Yes" | grep "/[a-zA-Z]*/F[a-zA-Z]*\*/[A-Z]" 
       /goingTo/FollowingPattern*/=Yes
       

    2. You said numbers too, so just put “[0-9]”

53. What really works is
    grep -n “s1” *.* |grep -n “s2”

54. how to get separate out files for multiple patterns [stings]

    1. Iterate over for each.

55. I need to calculate the received packets from .tr file.
    Problem is that one string is necessary for me but some unnecessary events are also counted that are not needed.

    So I want a solution.

    line1: r 0.500000000 _1_ RTR — 0 cbr 210 [0 0 0 0] ——- [1:0 5:0 32 0] [0] 0 0
    line 2: r 0.501408175 _3_ RTR — 0 AODV 48 [0 ffffffff 1 800] ——- [1:255 -1:255 30 0] [0x2 1 1 [5 0] [1 4]] (REQUEST)

    I want only line 1 but as I am searching for ‘^r’ only so both files are counting. Pls help me how can I search the line where 2 patterns are needed?

56. I want to use grep command for multiple patterns in a file and print a number of lines after each match into a new file. Say in the command
    $grep ‘Well\|MultiLayer\|Prediction’ PredResult.prn >List.txt

    – after ‘Well’ match I want to print 100 lines starting with pattern ’01/’,
    – after ‘MultiLayer’ match I do not want to print any line,
    – after ‘Prediction’ match I want to print 100 lines starting with pattern ’01/’.

    Please suggest a workaround.

57. egrep “pattern1|pattern2” filename
    egrep -e “pattern1|pattern2” filename

    The above(both) syntax works in Sun OS for searching multiple patterns in file

58. How can I search with a date string with a space?
    Like I was to search for ‘Jan 14’ and Username

59. Thanks for the super useful info.

60. Use grep -E “pattern1|pattern2”

61. Maybe stupid question but I can’t understand WHY this one works at all:

    $ grep 'warning\|error\|critical' /var/log/messages 

    Shouldn’t the \ mean it will escape the | and treat it as a string value of ‘|’? It works and treats | as the regular expression OR (alternation) function, yes, but it’s driving me crazy. I am thinking I should just egrep everything if I plan to use regular expressions because that usage makes no sense to me and the egrep usage does.

62. From this post:
    
grep -E 'warning|error|critical' /var/log/messages
grep -e warning -e error -e critical /var/log/messages


    should both OK!

63. Hi Guys,

    How to do that invert selection [grep -v] multiple string, without pipe. ?

    1. Use it as follows:

       egrep -v 'word1|word2' file

64. Hi,
    Need help!
    I need to grep “timeout” with sourrending 2 lines. (grep -C 2 “timeout” filename) is not working since using HP-UX.

    Please let me know if there are any other commands for HP-UX.

    Thanks,
    Nagaraj

65. Is there a way where i can get individual count using multiple strings..
    say i want to get the individual count of each word using
    grep -i warning|error|critical’ /var/log/messages

66. Thanks for this tutorial 👍

67. Thanks bro. it is very useful.

68. ps -ef | grep ‘8462|3705|1847|1739|1671|1650|1146|1108|1082’
    Will help to grep many strings in one command

69. how can i make grep on statement but it is contain more than line

70. write a unix command to List all files that have tab somewhere in their name?

71. Enter the command grep ‘if ’ bashrc. This will find every line in the file that contains an if followed by a blank space. How many lines did the statement find? Were any of the lines not actually if statements? (comments start with a #). You can obtain just the number of matches using grep –c. Repeat the command using –c to make sure you counted correctly!

72. Hi ,

    The below script is not working
    $ grep -e 'warning|error|critical' /var/log/messages

    so I tried to use ‘\|’ instead of ‘|’ alone
    $ grep -e 'warning\|error\|critical' /var/log/messages

    Then I got desired output… so does the above script varies based on OS ?? I am using
    Linux 3.0.101-0.47.93-default

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