Piping paths with different types of quotes for slash substitution

Question

I would like to use sed to convert a path with backslashes to the same path with forward slashes:

E.g. I would like to pipe \\path\to\file\ and obtain /path/to/file

None of the following commands work, and I can't tell why:

First attempt:

> echo '\\path\to\file\' | sed 's/\\/\//g'
/path   o
         ile/

Second attempt:

echo \\path\to\file\ | sed 's/\\/\//g' 
/pathtofile

Third attempt:

 echo "\\path\to\file\" | sed 's/\\/\//g'
dbquote>

I get a similar behavior if I try piping to | tr '\' '/'

I am looking for the correct answer and, if possible, for an explanation of why none of the attempts above worked. Not sure if it matters, but this is all on zsh 4.2.6 (x86_64-redhat-linux-gnu)

Thanks!

Answer 1

file='\\path\to\file\'
printf '%s\n' "$file" | tr -s '\\' /

zsh:

setopt extendedglob
print -r -- ${file//\\##/\/}

Answer 2

Don't use echo. The problem with echo is there are too many versions and each handles backslashes slightly differently. Yours is evidently interpreting the backslashes in your original string. If you just did

# first attempt
echo '\\path\to\file\'

I suspect you would see

\path   o
         ile\

Similarly in all your other attempts the problem is with your usage of echo and the interactions between echo and shell quoting and backslashes, and not with the second part of the pipe (the sed or tr).

The solution is to use printf instead - its behavior is much more consistent and portable since it is specified by POSIX.

printf '\\\\path\\to\\file\\\n'

gets you

\\path\to\file\