xdo

"Oh God, what did I do?"

You should probably never use this, unless you are so desperate to rename all your files, which I was. And in that case, make a backup.

The idea is to have a Unix-y tool to propogate actions across globbed arguments. This was made for executables that takes a variable length list of positional arguments, and feeds output into the last positional argument (such as mv and cp) or writes to standard out (such as head or tail).

In the case of mv and cp, the command is executed on each of the input files, with the final argument remaining constant (in that case, it is a directory). xdo allows these commands to be executed with different outputs, defined with a simplified wildcard substitution.

An optional argument for redirecting standard output allows commands like head to be used with the same wildcard syntax.

##Examples:

• I wanted to rename a folder full of wordcounts to reflect the fact that they were all unigrams, since I was about to add bigrams.

xdo mv "ngrams/*.csv" "ngrams/*_unigrams.csv"

• I wanted to slice off the first hundred listings from them, and store them each into their own files.

xdo head "ngrams/*.csv" "-n 100" -o "ngrams/*_head.csv"

Note: The glob and the arguments have to be quoted.

• The file extension can be accessed as a wildcard too.

##Wildcard expansion syntax ####Reserved characters: (these should not be present in filenames)

• *: The original filename, or a part of the filename, if used with a dot.
• #: The index of the globbing loop, an integer to add prefixes/suffixes to files

####Assumptions about usage:

• Rewriting original file extensions is something the user would want to do. If the destination has a file extension, it will be used to overwrite the file extension of the input. This allows transformations like xdo mv "*.csv" "*.tsv", if you misspelled all of your tab-delimited files, or some DUMB thing you would do.

• Rewriting filenames while preserving file extensions is NOT something the user would do. They are much more likely to be prepending to the filename. For that reason, xdo mv "*.*" "test.*" prepends all of the files with test. I have no idea if this is a good idea or not. It seems like a stupid edge case in retrospect, why did I waste my night on this?

• All paths are absolute from the current working directory, and substitition only happens at the file level, not the directory level.

##Testing

pip install nosetests. Run nosetests to test.

The symlink to xdo.py is there to facilitate testing.