Swap a line with another












2















I have the file



Line 1
Line 2 MATCH
Line 3
Line 4
Line 1
Line 2 MATCH
Line 3
Line 4


And I want to swap the line with "MATCH" and "Line 1" for every case. I tried to search in other questions, but those move the line with the match to the last line and I don't understand so well the code to remake my version for a final output like:



Line 2 MATCH
Line 1
Line 3
Line 4
Line 2 MATCH
Line 1
Line 3
Line 4









share|improve this question







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  • Is the line with "MATCH" always line two, hence to be swapped with the line before it?

    – Sparhawk
    8 hours ago











  • @Sparhawk Yes, it is.

    – TheAsker
    8 hours ago











  • @don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

    – TheAsker
    8 hours ago
















2















I have the file



Line 1
Line 2 MATCH
Line 3
Line 4
Line 1
Line 2 MATCH
Line 3
Line 4


And I want to swap the line with "MATCH" and "Line 1" for every case. I tried to search in other questions, but those move the line with the match to the last line and I don't understand so well the code to remake my version for a final output like:



Line 2 MATCH
Line 1
Line 3
Line 4
Line 2 MATCH
Line 1
Line 3
Line 4









share|improve this question







New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





















  • Is the line with "MATCH" always line two, hence to be swapped with the line before it?

    – Sparhawk
    8 hours ago











  • @Sparhawk Yes, it is.

    – TheAsker
    8 hours ago











  • @don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

    – TheAsker
    8 hours ago














2












2








2








I have the file



Line 1
Line 2 MATCH
Line 3
Line 4
Line 1
Line 2 MATCH
Line 3
Line 4


And I want to swap the line with "MATCH" and "Line 1" for every case. I tried to search in other questions, but those move the line with the match to the last line and I don't understand so well the code to remake my version for a final output like:



Line 2 MATCH
Line 1
Line 3
Line 4
Line 2 MATCH
Line 1
Line 3
Line 4









share|improve this question







New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












I have the file



Line 1
Line 2 MATCH
Line 3
Line 4
Line 1
Line 2 MATCH
Line 3
Line 4


And I want to swap the line with "MATCH" and "Line 1" for every case. I tried to search in other questions, but those move the line with the match to the last line and I don't understand so well the code to remake my version for a final output like:



Line 2 MATCH
Line 1
Line 3
Line 4
Line 2 MATCH
Line 1
Line 3
Line 4






text-processing sed






share|improve this question







New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question







New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question






New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 8 hours ago









TheAskerTheAsker

132




132




New contributor




TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor





TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






TheAsker is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.













  • Is the line with "MATCH" always line two, hence to be swapped with the line before it?

    – Sparhawk
    8 hours ago











  • @Sparhawk Yes, it is.

    – TheAsker
    8 hours ago











  • @don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

    – TheAsker
    8 hours ago



















  • Is the line with "MATCH" always line two, hence to be swapped with the line before it?

    – Sparhawk
    8 hours ago











  • @Sparhawk Yes, it is.

    – TheAsker
    8 hours ago











  • @don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

    – TheAsker
    8 hours ago

















Is the line with "MATCH" always line two, hence to be swapped with the line before it?

– Sparhawk
8 hours ago





Is the line with "MATCH" always line two, hence to be swapped with the line before it?

– Sparhawk
8 hours ago













@Sparhawk Yes, it is.

– TheAsker
8 hours ago





@Sparhawk Yes, it is.

– TheAsker
8 hours ago













@don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

– TheAsker
8 hours ago





@don_crissti but in the answer provided there, they only swap the line N with the line below. For swap line N with the line above, they swap the Line N-1 with the line below. There is some way to swap with the line above based on a pattern?

– TheAsker
8 hours ago










5 Answers
5






active

oldest

votes


















2














If the idea is to swap the MATCH line with the immediately preceding one, then something like this would do:



$ awk '!/MATCH/ { if (NR > 1) print prev; prev=$0} 
/MATCH/ {print $0;}
END {print prev}' < file
Line 2 MATCH
Line 1
Line 3
Line 4
Line 2 MATCH
Line 1
Line 3
Line 4


The script holds the previous line in prev, printing and updating it on the non-matching lines. On lines matching the pattern, it prints the current line, leaving the previous in the variable to be printed next.



Special cases for the first line (NR==1) when there's no previous line to print, and for the END when we print the held line.






share|improve this answer































    2














    Using ed:



    $ printf 'g/MATCH/m-2n,pn' | ed -s file
    Line 2 MATCH
    Line 1
    Line 3
    Line 4
    Line 2 MATCH
    Line 1
    Line 3
    Line 4


    The m command moves the current line to the subsequent target address. Here, we find all lines matching MATCH (it's the g in front of the regular expression that makes this a "global" operation), and for each line move it one line up. The effect is that the MATCH lines swap places with the immediately preceding lines. We use -2 since the m command moves the line to after the targeted line.



    The final ,p in the editing script just displays the modified editing buffer.






    share|improve this answer

































      0














      Using sed with a N;P;D cycle:



      sed -e '$!N;s/(Line 1)(n)(.*MATCH.*)/321/;t' -e 'P;D' infile


      This will swap only if the line with MATCH is preceded by Line 1: the t without label branches to the end of script if successful and so it avoids another swap if any Line 1 is followed by consecutive lines with MATCH. Adjust the regex for any leading/trailing blanks.






      share|improve this answer































        0














        Using sed editor, we can swap two lines one of which contains Match keyword with the one preceding it.



         $ sed -e '
        /MATCH/!{
        x;1!p;$!d;g;q
        }
        $G
        ' input.txt

        Line 2 MATCH
        Line 1
        Line 3
        Line 4
        Line 2 MATCH
        Line 1
        Line 3
        Line 4





        share|improve this answer































          -1














          sed "s/line 2 match//g"|sed "s/line 1/line 2 matchn&/g"



          Above command worked fine






          share|improve this answer
























          • The lines with MATCH should swap places with the preceding lines.

            – Kusalananda
            5 hours ago











          Your Answer








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          5 Answers
          5






          active

          oldest

          votes








          5 Answers
          5






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          2














          If the idea is to swap the MATCH line with the immediately preceding one, then something like this would do:



          $ awk '!/MATCH/ { if (NR > 1) print prev; prev=$0} 
          /MATCH/ {print $0;}
          END {print prev}' < file
          Line 2 MATCH
          Line 1
          Line 3
          Line 4
          Line 2 MATCH
          Line 1
          Line 3
          Line 4


          The script holds the previous line in prev, printing and updating it on the non-matching lines. On lines matching the pattern, it prints the current line, leaving the previous in the variable to be printed next.



          Special cases for the first line (NR==1) when there's no previous line to print, and for the END when we print the held line.






          share|improve this answer




























            2














            If the idea is to swap the MATCH line with the immediately preceding one, then something like this would do:



            $ awk '!/MATCH/ { if (NR > 1) print prev; prev=$0} 
            /MATCH/ {print $0;}
            END {print prev}' < file
            Line 2 MATCH
            Line 1
            Line 3
            Line 4
            Line 2 MATCH
            Line 1
            Line 3
            Line 4


            The script holds the previous line in prev, printing and updating it on the non-matching lines. On lines matching the pattern, it prints the current line, leaving the previous in the variable to be printed next.



            Special cases for the first line (NR==1) when there's no previous line to print, and for the END when we print the held line.






            share|improve this answer


























              2












              2








              2







              If the idea is to swap the MATCH line with the immediately preceding one, then something like this would do:



              $ awk '!/MATCH/ { if (NR > 1) print prev; prev=$0} 
              /MATCH/ {print $0;}
              END {print prev}' < file
              Line 2 MATCH
              Line 1
              Line 3
              Line 4
              Line 2 MATCH
              Line 1
              Line 3
              Line 4


              The script holds the previous line in prev, printing and updating it on the non-matching lines. On lines matching the pattern, it prints the current line, leaving the previous in the variable to be printed next.



              Special cases for the first line (NR==1) when there's no previous line to print, and for the END when we print the held line.






              share|improve this answer













              If the idea is to swap the MATCH line with the immediately preceding one, then something like this would do:



              $ awk '!/MATCH/ { if (NR > 1) print prev; prev=$0} 
              /MATCH/ {print $0;}
              END {print prev}' < file
              Line 2 MATCH
              Line 1
              Line 3
              Line 4
              Line 2 MATCH
              Line 1
              Line 3
              Line 4


              The script holds the previous line in prev, printing and updating it on the non-matching lines. On lines matching the pattern, it prints the current line, leaving the previous in the variable to be printed next.



              Special cases for the first line (NR==1) when there's no previous line to print, and for the END when we print the held line.







              share|improve this answer












              share|improve this answer



              share|improve this answer










              answered 7 hours ago









              ilkkachuilkkachu

              59k892166




              59k892166

























                  2














                  Using ed:



                  $ printf 'g/MATCH/m-2n,pn' | ed -s file
                  Line 2 MATCH
                  Line 1
                  Line 3
                  Line 4
                  Line 2 MATCH
                  Line 1
                  Line 3
                  Line 4


                  The m command moves the current line to the subsequent target address. Here, we find all lines matching MATCH (it's the g in front of the regular expression that makes this a "global" operation), and for each line move it one line up. The effect is that the MATCH lines swap places with the immediately preceding lines. We use -2 since the m command moves the line to after the targeted line.



                  The final ,p in the editing script just displays the modified editing buffer.






                  share|improve this answer






























                    2














                    Using ed:



                    $ printf 'g/MATCH/m-2n,pn' | ed -s file
                    Line 2 MATCH
                    Line 1
                    Line 3
                    Line 4
                    Line 2 MATCH
                    Line 1
                    Line 3
                    Line 4


                    The m command moves the current line to the subsequent target address. Here, we find all lines matching MATCH (it's the g in front of the regular expression that makes this a "global" operation), and for each line move it one line up. The effect is that the MATCH lines swap places with the immediately preceding lines. We use -2 since the m command moves the line to after the targeted line.



                    The final ,p in the editing script just displays the modified editing buffer.






                    share|improve this answer




























                      2












                      2








                      2







                      Using ed:



                      $ printf 'g/MATCH/m-2n,pn' | ed -s file
                      Line 2 MATCH
                      Line 1
                      Line 3
                      Line 4
                      Line 2 MATCH
                      Line 1
                      Line 3
                      Line 4


                      The m command moves the current line to the subsequent target address. Here, we find all lines matching MATCH (it's the g in front of the regular expression that makes this a "global" operation), and for each line move it one line up. The effect is that the MATCH lines swap places with the immediately preceding lines. We use -2 since the m command moves the line to after the targeted line.



                      The final ,p in the editing script just displays the modified editing buffer.






                      share|improve this answer















                      Using ed:



                      $ printf 'g/MATCH/m-2n,pn' | ed -s file
                      Line 2 MATCH
                      Line 1
                      Line 3
                      Line 4
                      Line 2 MATCH
                      Line 1
                      Line 3
                      Line 4


                      The m command moves the current line to the subsequent target address. Here, we find all lines matching MATCH (it's the g in front of the regular expression that makes this a "global" operation), and for each line move it one line up. The effect is that the MATCH lines swap places with the immediately preceding lines. We use -2 since the m command moves the line to after the targeted line.



                      The final ,p in the editing script just displays the modified editing buffer.







                      share|improve this answer














                      share|improve this answer



                      share|improve this answer








                      edited 5 hours ago

























                      answered 6 hours ago









                      KusalanandaKusalananda

                      130k17247407




                      130k17247407























                          0














                          Using sed with a N;P;D cycle:



                          sed -e '$!N;s/(Line 1)(n)(.*MATCH.*)/321/;t' -e 'P;D' infile


                          This will swap only if the line with MATCH is preceded by Line 1: the t without label branches to the end of script if successful and so it avoids another swap if any Line 1 is followed by consecutive lines with MATCH. Adjust the regex for any leading/trailing blanks.






                          share|improve this answer




























                            0














                            Using sed with a N;P;D cycle:



                            sed -e '$!N;s/(Line 1)(n)(.*MATCH.*)/321/;t' -e 'P;D' infile


                            This will swap only if the line with MATCH is preceded by Line 1: the t without label branches to the end of script if successful and so it avoids another swap if any Line 1 is followed by consecutive lines with MATCH. Adjust the regex for any leading/trailing blanks.






                            share|improve this answer


























                              0












                              0








                              0







                              Using sed with a N;P;D cycle:



                              sed -e '$!N;s/(Line 1)(n)(.*MATCH.*)/321/;t' -e 'P;D' infile


                              This will swap only if the line with MATCH is preceded by Line 1: the t without label branches to the end of script if successful and so it avoids another swap if any Line 1 is followed by consecutive lines with MATCH. Adjust the regex for any leading/trailing blanks.






                              share|improve this answer













                              Using sed with a N;P;D cycle:



                              sed -e '$!N;s/(Line 1)(n)(.*MATCH.*)/321/;t' -e 'P;D' infile


                              This will swap only if the line with MATCH is preceded by Line 1: the t without label branches to the end of script if successful and so it avoids another swap if any Line 1 is followed by consecutive lines with MATCH. Adjust the regex for any leading/trailing blanks.







                              share|improve this answer












                              share|improve this answer



                              share|improve this answer










                              answered 7 hours ago









                              don_crisstidon_crissti

                              50.9k15135163




                              50.9k15135163























                                  0














                                  Using sed editor, we can swap two lines one of which contains Match keyword with the one preceding it.



                                   $ sed -e '
                                  /MATCH/!{
                                  x;1!p;$!d;g;q
                                  }
                                  $G
                                  ' input.txt

                                  Line 2 MATCH
                                  Line 1
                                  Line 3
                                  Line 4
                                  Line 2 MATCH
                                  Line 1
                                  Line 3
                                  Line 4





                                  share|improve this answer




























                                    0














                                    Using sed editor, we can swap two lines one of which contains Match keyword with the one preceding it.



                                     $ sed -e '
                                    /MATCH/!{
                                    x;1!p;$!d;g;q
                                    }
                                    $G
                                    ' input.txt

                                    Line 2 MATCH
                                    Line 1
                                    Line 3
                                    Line 4
                                    Line 2 MATCH
                                    Line 1
                                    Line 3
                                    Line 4





                                    share|improve this answer


























                                      0












                                      0








                                      0







                                      Using sed editor, we can swap two lines one of which contains Match keyword with the one preceding it.



                                       $ sed -e '
                                      /MATCH/!{
                                      x;1!p;$!d;g;q
                                      }
                                      $G
                                      ' input.txt

                                      Line 2 MATCH
                                      Line 1
                                      Line 3
                                      Line 4
                                      Line 2 MATCH
                                      Line 1
                                      Line 3
                                      Line 4





                                      share|improve this answer













                                      Using sed editor, we can swap two lines one of which contains Match keyword with the one preceding it.



                                       $ sed -e '
                                      /MATCH/!{
                                      x;1!p;$!d;g;q
                                      }
                                      $G
                                      ' input.txt

                                      Line 2 MATCH
                                      Line 1
                                      Line 3
                                      Line 4
                                      Line 2 MATCH
                                      Line 1
                                      Line 3
                                      Line 4






                                      share|improve this answer












                                      share|improve this answer



                                      share|improve this answer










                                      answered 1 hour ago









                                      Rakesh SharmaRakesh Sharma

                                      302113




                                      302113























                                          -1














                                          sed "s/line 2 match//g"|sed "s/line 1/line 2 matchn&/g"



                                          Above command worked fine






                                          share|improve this answer
























                                          • The lines with MATCH should swap places with the preceding lines.

                                            – Kusalananda
                                            5 hours ago
















                                          -1














                                          sed "s/line 2 match//g"|sed "s/line 1/line 2 matchn&/g"



                                          Above command worked fine






                                          share|improve this answer
























                                          • The lines with MATCH should swap places with the preceding lines.

                                            – Kusalananda
                                            5 hours ago














                                          -1












                                          -1








                                          -1







                                          sed "s/line 2 match//g"|sed "s/line 1/line 2 matchn&/g"



                                          Above command worked fine






                                          share|improve this answer













                                          sed "s/line 2 match//g"|sed "s/line 1/line 2 matchn&/g"



                                          Above command worked fine







                                          share|improve this answer












                                          share|improve this answer



                                          share|improve this answer










                                          answered 6 hours ago









                                          Praveen Kumar BSPraveen Kumar BS

                                          1,472138




                                          1,472138













                                          • The lines with MATCH should swap places with the preceding lines.

                                            – Kusalananda
                                            5 hours ago



















                                          • The lines with MATCH should swap places with the preceding lines.

                                            – Kusalananda
                                            5 hours ago

















                                          The lines with MATCH should swap places with the preceding lines.

                                          – Kusalananda
                                          5 hours ago





                                          The lines with MATCH should swap places with the preceding lines.

                                          – Kusalananda
                                          5 hours ago










                                          TheAsker is a new contributor. Be nice, and check out our Code of Conduct.










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