mjhjmtu

I am trying to replace all folders in a path with ".."
This is part of a bigger script that will eventually replace some absolute paths into relative paths.

The expected output should look like this:

/ABCDdasda234sEA/asdas2das/asdasf34234/ => /../../../
/ABCDdasda234sEA/asdas2das/asdasf34234/124551assdfa/ => /../../../../

I tried various regex but couldn't get to match correctly, because last "/" is considered ending of the string instead of matching multiple times:

[root@test]# sed "s/^/.*/$//..//g" <<< "/ABCDdasda234sEA/asdasdas/asdasf34234/"

/../

1) The .* will eat everything including the following slashes, so use [^/]* instead (any number of characters except for the slash)

2) To avoid the + (for "one or more occurences") which is not available in all sed version simply add a dot requiring at least one character. You don't need another [^/] here if you trust that there is no //

3) Just for beautification: If the pattern or replacement contain a slash, it's easier to read if you use a different delimiter for the s command like _ or #

All together:

sed 's_/.[^/]*_/.._g'

awk -F/ -v OFS=/ 'for (i=1; i<=NF; i++) if (length($i)) $i = ".."1' <<END
/ABCDdasda234sEA/asdas2das/asdasf34234/
/ABCDdasda234sEA/asdas2das/asdasf34234/124551assdfa/
END

/../../../
/../../../../

I found two more methods meanwhile:

sed 's:/[[:alnum:]]*:../:g' <<< "/ABCDdasda234sEA/asdasdas/asdasf34234/42346346346/" | sed 's:^..::g'


awk -F'/' 'for( i = 2; i <= NF-1; i++ ) printf "/../" ' <<< "/ABCDdasda234sEA/asdasdas/asdasf34234/asfasddfg/2345555/" | sed 's//////g'

Also to include other special characters such as "_":

sed 's:/[[:alnum:]_]*:../:g' <<< "/ABCDdasda234sEA/asdasdas/asdasf34234/42346346$346/" | sed 's:^..::g'

Some versions of sed do not accept the advanced features of regular expressions (e.g. + or ) by default. On my system, + works ok.

Also, you may replace w here with [^/], since file names may contain blanks.