Sed - replace words

Question

I have a problem with replacing string.

|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631

I want to find occurrence of Svc till | appears and swap place with Stm till | appears.

My attempts went to replacing characters and this is not my goal.

you can [edit](https://stackoverflow.com/posts/40422418/edit) your question too :) do add expected output for clarity as well as add the command you tried — Sundeep, Nov 04 '16 at 12:29

score 2 · Answer 1 · answered Nov 04 '16 at 12:38

awk -F'|' -v OFS='|' 
      '{a=b=0;
        for(i=1;i<=NF;i++){a=$i~/^Stm=/?i:a;b=$i~/^Svc=/?i:b}
        t=$a;$a=$b;$b=t}7' file

outputs:

|Svc=101|Seq=2|Num=2|Stm=2|MsgSize(514)=514|MsgType=556|SymbolIndex=16631

the code exchange the column of Stm.. and Svc.., no matter which one comes first.

c3st7n · Answer 2 · 2016-11-04T13:48:50.657

0

You need to use capture groups and backreferences in a string substition.

The below will swap the 2:

echo '|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631' | sed 's/$Stm.*|$$.*$$Svc.*|$/\3\2\1/'

As pointed out in the comment from @Kent, this will not work if the strings were not in that order.

edited Nov 04 '16 at 13:48

answered Nov 04 '16 at 12:29

c3st7n

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what if `Svc` comes first – Kent Nov 04 '16 at 12:39
you have got a typo, you have escaped `|` which shouldn't have been as you are using BRE – Sundeep Nov 04 '16 at 12:56
Removed the unneeded `|` based on your comment @Sundeep – c3st7n Nov 04 '16 at 13:48

score 0 · Answer 3 · answered Nov 04 '16 at 12:49

If perl solution is okay, assumes only one column matches each for search terms

$ cat ip.txt 
|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631

$ perl -F'\|' -lane '
@i = grep { $F[$_] =~ /Svc|Stm/ } 0..$#F;
$t=$F[$i[0]]; $F[$i[0]]=$F[$i[1]]; $F[$i[1]]=$t;
print join "|", @F;
' ip.txt
|Svc=101|Seq=2|Num=2|Stm=2|MsgSize(514)=514|MsgType=556|SymbolIndex=16631

-F'\|' -lane split input line on |, see also Perl flags -pe, -pi, -p, -w, -d, -i, -t?
@i = grep { $F[$_] =~ /Svc|Stm/ } 0..$#F get index of columns matching Svc and Stm
$t=$F[$i[0]]; $F[$i[0]]=$F[$i[1]]; $F[$i[1]]=$t swap the two columns
- Or use ($F[$i[0]], $F[$i[1]]) = ($F[$i[1]], $F[$i[0]]); courtesy How can I swap two Perl variables
print join "|", @F print the modified array

Sed - replace words

3 Answers3