/usr/share/doc/m4/examples/join.m4 is in m4 1.4.18-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | divert(`-1')
# join(sep, args) - join each non-empty ARG into a single
# string, with each element separated by SEP
define(`join',
`ifelse(`$#', `2', ``$2'',
`ifelse(`$2', `', `', ``$2'_')$0(`$1', shift(shift($@)))')')
define(`_join',
`ifelse(`$#$2', `2', `',
`ifelse(`$2', `', `', ``$1$2'')$0(`$1', shift(shift($@)))')')
# joinall(sep, args) - join each ARG, including empty ones,
# into a single string, with each element separated by SEP
define(`joinall', ``$2'_$0(`$1', shift($@))')
define(`_joinall',
`ifelse(`$#', `2', `', ``$1$3'$0(`$1', shift(shift($@)))')')
divert`'dnl
|