Question

I’d like to change the path and extension of a file in a variable at once e.g. do the following

for F in $( find /foo/bar -name "*.ext" ); do 
  Ftmp=${F%.ext}
  cp $F ${Ftmp//bar/b0r}.tmp 
done

without a temporary variable

Can two string operations be applied at once with bash only means?

Answer 1

Use the Bash temporary variable

$_    Temporary variable; initialized to pathname of script or program
      being executed. Later, stores the last argument of previous command.
      Also stores name of matching MAIL file during mail checks.

for F in $( find /foo/bar -name "*.ext" )
do
  : ${F%.ext}
  cp $F ${_//bar/b0r}.tmp
done