Bash – find, xargs and mv: renaming files with double-quotes, expansion and bash precedence issue

bashfindshell-scriptxargs

Ok, I'm simply trying to strip out double-quotes in my filenames. Here's the command I came up with (bash).

$ find . -iname "*\"*" -print0 | xargs -0 -I {} mv {} {} | tr -d \"

The problem is the 'mv {} {} | tr -d \"' part. I think it's a precedence problem: bash seems to be interpreting as (mv {} {}) | tr -d \"), and what I'm left with are both filenames stripped of double-quotes. That's not what I want, obviously, because then it fails to rename the file. Instead, I want the first filename to have the quotes, and the second not to, more like this: mv {} ({} | tr -d \").

How do I accomplish this? I've tried brackets and curly braces, but I'm not really sure what I'm doing when it comes to explicitly setting command execution precedence.

Best Answer

Assuming you have the rename command installed, use:

find . -name '*"*' -exec rename 's/"//g' {} +

The rename command takes a Perl expression to produce the new name. s/"//g performs a global substitution of the name, replacing all the quotes with an empty string.

To do it with mv you need to pipe to a shell command, so you can execute subcommands:

find . -name '*"*' -exec sh -c 'mv "$0" "$(printf %s "$0" | tr -d "\"")"' {} \;

What you wrote pipes the output of xargs to tr, it doesn't use tr to form the argument to mv.

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Bash – Configure bash globbing

Unfortunately, I must answer my own question. It was GLOBIGNORE. From the man page:

A colon-separated list of patterns defining the set of filenames to be ignored by pathname expansion. If a filename matched by a pathname expansion pattern also matches one of the patterns in GLOBIGNORE, it is removed from the list of matches.

Bash Scripting – Handle Paths with Spaces and Wildcards

Inside quotes, the * will not expand to a list of files. To use such a wildcard successfully, it must be outside of quotes.

Even if the wildcard did expand, the expression "${FILES}" would result in a single string, not a list of files.

One approach that would work would be:

#!/bin/bash
DIR="/home/john/my directory/"
for f in "$DIR"/*.txt
do
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done

In the above, file names with spaces or other difficult characters will be handled correctly.

A more advanced approach could use bash arrays:

#!/bin/bash
FILES=("/home/john/my directory/"*.txt)
for f in "${FILES[@]}"
do
  echo "${f}"
done

In this case, FILES is an array of file names. The parens surrounding the definition make it an array. Note that the * is outside of quotes. The construct "${FILES[@]}" is a special case: it will expand to a list of strings where each string is one of the file names. File names with spaces or other difficult characters will be handled correctly.

Best Answer

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Bash Scripting – Handle Paths with Spaces and Wildcards

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