How to change double hyphen to single hyphen of file names

command linefilesrename

I have been using the rename command to get control over my naming conventions across my system. In converting spaces in file names to hyphens, I have inadvertently created consecutive hyphens in some file names. These are proving difficult to remedy using the rename command.

I have tried unsuccessfully with several different iterations of the following:

rename 's/--/-/g'

I do understand that double hyphens are reserved for end of arguments but a backslash escape doesn't seem to work here and I'm out of other ideas.

I am relatively new to command line processing so your patience is appreciated.

Best Answer

To squash multiple hyphens (one hyphen followed by one or more hyphens) into a single one for all files in the current directory use:

rename 's/--+/-/g' -- *

The -- is important if files start with a hyphen, otherwise they would be interpreted as command line arguments. The * expands to the list of files in the current directory.

Related Solutions

Command Line Rename – How to Remove URI Encoding from File Names

On Debian and derivatives (including Ubuntu), you could use rename, which applies a Perl expression to each file name.

rename 's/%20/ /g' L*
        |  |  | |   |
        |  |  | |   +--- Files to match
        |  |  | +------- globally
        |  |  +--------- with space
        |  +------------ %20
        +--------------- Substitute

I would consider using underscore instead of space – as it generally makes life easier in the cli world.

To generalise to all URI encoding:

rename 'use URI::Escape; $_ = uri_unescape $_' *%*

Change some file names (prefix to postfix)

This will work if we assume everything up to the first underscore to be the prefix.

for f in *.png; do
    new=$(echo "$f" | sed -r 's/^([^_]*)_(.*)\.(.*)$/\2_\1.\3/');
    echo "Renaming: $f => $new";
    #mv $f $new
done

Remove the # in front of mv if you're happy with the output.

With prename it would be a little easier:

prename -n 's/^([^_]*)_(.*)\.(.*)$/$2_$1.$3/'

If t_ is always the prefix, change to this pattern:

for f in t_*.png; do
    new=$(echo "$f" | sed -r 's/^t_(.*)\.(.*)$/\1_t.\2/');
    echo "Renaming: $f => $new";
    #mv $f $new
done

Best Answer

Related Solutions

Command Line Rename – How to Remove URI Encoding from File Names

Change some file names (prefix to postfix)

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