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Bash command to insert contents of one file into a specific part of another file

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  • 19-06-2019 11:21am
    #1
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭ 


    cat file_to_insert
1
2
cat original_file
a
b
c


    I want to put the contents of file_to_insert on the original file between b and c

    So it would look like
    a
b
1
2
c


Comments

  • Options
    #2
    Skrynesaver
    Registered Users Posts: 1,109 ✭✭✭Skrynesaver 


    $ split -l 2 original_file original_part_ && cat original_part_aa file_to_insert original_part_ab
a
b
1
2
c


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    #3
    28064212
    Registered Users Posts: 10,494 ✭✭✭✭28064212 


    sed "/^b$/r file_to_insert" original_file
    This will insert the contents of file_to_insert after every line that exactly matches 'b'.

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    #4
    srsly78
    Registered Users Posts: 7,157 ✭✭✭srsly78


    Use head/tail and grep to do this. Grep to find the line before/after the special section.

    https://linux.die.net/man/1/grep - look at the -A and -B options.


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    #5
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    Cheers y'all. Settled on the sed command


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    #6
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    One more query on this
    sed "/^${last_string}$/r ${tmp_symlinks_file_part_2}" /var/tmp/sym_links.ini.$$

    Is there a way to do the replacement at X lines after the instance of the last string.

    In my case, i want to do it 6 lines down


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  • Options
    #7
    srsly78
    Registered Users Posts: 7,157 ✭✭✭srsly78


    Yes, with the grep -A or -B options.

    Use grep to extract the section you want to change, then pipe this to sed.


  • Options
    #8
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    srsly78 wrote: »
    Yes, with the grep -A or -B options.

    Sorry to sound silly but how to shoehorn that into the current command?


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    #9
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    Answering my own q
    last_details=$(grep -A8 ${last_string} /var/tmp/sym_links.ini.$$)
        sed "/^${last_details}$/r ${tmp_symlinks_file_part_2}" /var/tmp/sym_links.ini.$$ > /var/tmp/sym_links.ini.$$.tmp2


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    #10
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    Seems to have trouble doing a multi line sed (as the grep gives us a multiline variable)


    sed: -e expression #1, char 24: unterminated address regex

    last_details=$(grep -A7 ${last_string} /var/tmp/sym_links.ini.$$)
sed "/^${last_details}$/r ${tmp_symlinks_file_part_2}" /var/tmp/sym_links.ini.$$ > /var/tmp/sym_links.ini.$$.tmp2


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    #11
    srsly78
    Registered Users Posts: 7,157 ✭✭✭srsly78


    Pipe grep -A to head -n 1 to get one line.


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  • Options
    #12
    veryangryman
    Registered Users Posts: 5,542 ✭✭✭veryangryman


    Similar ish query
    sed "/^\[DWH_DBSPACES_LOCATION\]$/r ${sysmain_content}" /var/tmp/sym_links.ini.$$ > /var/tmp/sym_links.ini.$$.tmp1

    How to alter this so that [DWH_DBSPACES_LOCATION] appears at the end rathjer than the start of the replaced string


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