Question on grepping multiple words in a line

This is a discussion on Question on grepping multiple words in a line within the Linux Programming forums, part of the Platform Specific Boards category; I'm trying have grep both the words 'cdalten' and "bash'. The closest I got was being able to grep either ...

  1. #1
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    Question on grepping multiple words in a line

    I'm trying have grep both the words 'cdalten' and "bash'. The closest I got was being able to grep either one of them like below.

    [cdalten@localhost ~]$ w | grep -E 'cdalten|bash'
    cdalten pts/1 :0.0 05Apr09 6days 0.36s 0.36s bash
    cdalten pts/2 :0.0 05Apr09 5days 2.24s 1.88s python
    cdalten pts/3 :0.0 16:11 7:55 0.64s 0.13s python
    cdalten pts/4 :0.0 17:05 0.00s 0.49s 0.03s w
    cdalten pts/5 :0.0 Thu19 32:14m 0.89s 0.89s bash
    What's the magical regex expression that I pass to grep so that I get the following instead

    cdalten pts/1 :0.0 05Apr09 6days 0.36s 0.36s bash
    cdalten pts/5 :0.0 Thu19 32:14m 0.89s 0.89s bash

  2. #2
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    Code:
    "[cdalten|bash]"
    ?

  3. #3
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    I generally do this by running "grep first | grep second", but I'm generally lazy when it comes to learning advanced expressions for tools that can easily be done by typing a bit more [I generally use this mostly when I find that the first grep got me far to much, and it's often easier to just add a "| grep somethingelse" onto the existing line, than it is to reform the expression (and you can use "grep -v someword" to only accept lines that do NOT contain someword - e.g. list all processes NOT bash: "w | grep cdalten | grep -v bash").

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    Mats
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    Please don't PM me for help - and no, I don't do help over instant messengers.

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    I think he meant "A OR B" not "A AND B".

    [edit]Oh nvm, I think you are right.[/edit]

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    Quote Originally Posted by cyberfish View Post
    I think he meant "A OR B" not "A AND B".

    [edit]Oh nvm, I think you are right.[/edit]
    Yeah, I want grep to return if both 'A AND B' are true

  6. #6
    spurious conceit MK27's Avatar
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    Code:
    cat txt | grep 'bash' | grep 'cdalten'
    There is no advantage to using a regular expression with this, but if you want to, there's always
    Code:
    cat txt | perl -ne 'if ((/bash/) && (/cdalten/)) {print $_}'
    This one works too but is sensitive to whitespace at the end of line:
    Code:
    cat txt | perl -ne 'if (/^cdalten.*bash$/) {print $_}'
    Last edited by MK27; 04-12-2009 at 11:43 AM.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  7. #7
    Captain Crash brewbuck's Avatar
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    Regular languages support conjunction, but I've never seen it in any regex syntax I've used. I do the same thing matsp does -- two greps.
    Code:
    //try
    //{
    	if (a) do { f( b); } while(1);
    	else   do { f(!b); } while(1);
    //}

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