Question

Hello I’m seeking a Perl one-liner if possible, to scan all of our Javascript files, to find so-called “rogue commas”. That is, commas that come at the end of an array or object data structure, and therefore commas that come immediately before either an ‘]’ or ‘}’ character.

The main challenge I’m encountering is how to make the regex that checks for ] or } non-greedy. The regex needs to span multiple lines, since the comma could end one line, followed by the } or ] on the next line, but I’ve figured out how to do that with the help of the book Minimal Perl.

Also, I’d like to be able to pipe a number of files to this Perl regex (via find/xargs), and so I’d like to print the name of the input file, and the line number within that file.

Below are various attempts of mine that are not particularly close to working straight from my bash history. Thanks in advance:

find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+$/ and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+/ and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+\]/ and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+[\]\}]/ and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+[\]\}]/ and print $_;' | wc -l find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+[\]\}]/ and print $_;' | wc -l find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+}/ and print $_;' | wc -l find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+}?/ and print $_;' | wc -l find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,\s+}+?/ and print $_;' | wc -l find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,$/' and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/,$/ and print $_;' find winhome/workspace/SsuExt4Zoura/quotetool/js
-name "*.js" | xargs perl -00 -wnl -e '/\,$/ and print $_;'

Answer 1

With the -00 switch, you change the record separator, and (probably) get the whole file in one line, which allows you to find multi-line trailing commas. However, it also makes the print $_ print the whole line. What you probably want is printing the file name:

print $ARGV if /,\s*[\]\}]/;