I am trying to write a script that takes a directory as a command line parameter and iterates over the files in the directory changing their extension to .bu .
I thought this would work but I'm getting the output '.bu' is not a target directory
#!/bin/bash for f in $1; do mv "$f".* .bu done 4 Answers
#!/bin/bash cd $1 for f in *; do mv "$f" "${f%.*}.bu" done Try that instead (assuming that $1 is a folder):
for f in $1/*; do mv "$f" "$f.bu" done Or use the rename utility:
rename -v 's/$/\.bu/' $1/* Those commands add an extension. If you want to change the existing extension use that:
rename -v 's/\.[^\.]+$/\.bu/' $1/* Taking the KISS approach, I would recommend the following script
#! /bin/bash cd $1; rename 's/$/\.bu/' * This will change working directory to the first parameter and then add a .bu extension to all files. This nullifies the need of for loop.
EDIT:
If you want to change the extension(instead of just adding it), you can try
rename 's/\..*$/\.bu/' * command instead, in the above script.
$1 within a bash script is a reference to the fist argument passed from the command line, so you're actually trying to process a single folder.
There are answers already about how to solve your problem using pure bash, but I'd like to add that if you need a better filtering of what is being processed you can use find with some options to select the files to be processed:
find <path_to_directory> -maxdepth 1 -type f *<path_to_directory> = path to the directory
Then loop over the list of files using stdin redirection:
#!/bin/bash while read file do rename 's/\..*/\.bu/' $file done <<< $(find $1 -maxdepth 1 -type f) 
