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bashshellunixawkex

Using ex editor to increment a number following a pattern in a file

Am aware of how to use the ex editor in syntaxes like this answer to do minor editing of files in place.

For example, as mentioned in the answer, assuming I have a file content as below:-

$ cat input-file
patternGoingDown
foo
bar
foo
bar

Running a command using ex, like

$ printf "%s\n" '/patternGoingDown' 'd' '/foo' 'n' 'put' 'wq' | ex file
$ cat file
foo
bar
foo
patternGoingDown
bar

will move the pattern patternGoingDown after the second occurrence of foo. My requirement is to adopt a similar logic to increment a number after a pattern.

Example:-

$ cat input-file
The number is now number(60)

Is it possible to use the ex editor to increment the number from 60 to 61like

$ cat input-file
The number is now number(61)

Though there is a ex-editor help page available, I can't figure out how to

  1. Parse the next character after search pattern, number in this case
  2. Increment to 61 which I can normally do via Ctrl+A when using vi editor.

I am aware there are other tools for this job, but I particularly need to use ex editor in the syntax I have mentioned.

Solution

  • This is tricky because Vim is not really suited to this. Awk is, but POSIX Awk does not do in place, so you have to use both:

    ex -sc '%!awk "\
{\
  match(\$0, /[[:digit:]]+/)\
  j = substr(\$0, RSTART, RLENGTH)\
  sub(j, ++j)\
}\
1\
"' -cx file