Tr
From MohidWiki
Tr is a little linux utility which translates standard input and returns in standard output. It is useful for easily converting from uppercase to lowercase, etc...
Examples
>for i in `find | grep Nomfich`; do j=`echo $i | tr [Nom] [nom]`; if [ $i != $j ]; then mv $i $j; fi; done;
This bash line transforms the Nomfich_*.dat files into nomfich_*.dat
> cat somefile.txt | tr -cd [:graph:]
The above command deletes all non-printable characters (good for chomping a string...)
> tr -d "\r\n" file1
The above command joins all lines from text input.
> tr -dc [:print:]
The above command removes all non-printable characters (printable characters include white spaces). This means that it will effectively concatenate all lines coming from a text input.