How to edit filenames in rc scripts without sed

How to edit filenames in rc scripts without sed

[Vincent Broman]

One of the csh features I find useful, and don't know how
to emulate easily in rc, is the variable substitution with
modifiers.  This lets you edit filenames to a certain degree
without execing sed all over the place.  E.g. undoing patches with:

foreach f (*.orig)
  mv $f $f:r
end

is nicer than

for ( f in *.orig ) mv $f `{echo $f | sed -e 's/\.[a-z]*$//'}

I've tried thinking up ways to get this effect by manipulating
the IFS to include '.' but I still get `{echo $f| ...stuff... }

Any ideas how to do basic filename modifications cleanly in rc?

Vincent Broman,  code 572 Bayside                        Phone: +1 619 553 1641
Naval Command Control and Ocean Surveillance Center, RDT&E Div.
San Diego, CA  92152-6147,  USA                          Email: broman@nosc.mil

Re: How to edit filenames in rc scripts without sed

[Alan Watson]

I concur with Steve.

However, I would like to point out one possible problem with basename
in this regard -- many basename executables are /bin/sh scripts which
call expr three times.  On my machine, the difference in speed between
the /bin/sh-based system basename and the pure-binary GNU basename is a
factor of 4 (which is the difference in the number of fork/exec
pairs).  

Anything based on ifs separation will probably come to grief on file
names containing repeated dots, such as `foo..bar'.

Alan.

Re: How to edit filenames in rc scripts without sed

[Steve_Kilbane]

For the (vaguely frequent) mv and cp commands, i use specialised commands
that allow wildcards, called 'move' and 'copy':

; mv '*.c' '*.c.old'

for anything else, i'm into the once-per-month-if-that kind of command, and
using sed's quicker than thinking about it:-).

steve