Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!dsac.dla.mil!dsacg3.dsac.dla.mil!nts0302
From: nts0302@dsacg3.dsac.dla.mil (Bob Fisher)
Newsgroups: comp.unix.questions
Subject: Re: How read a line of a file from C-shell?
Message-ID: <2641@dsacg3.dsac.dla.mil>
Date: 22 Oct 90 12:17:34 GMT
References: <8900@ncar.ucar.edu>
Organization: Defense Logistics Agency Systems Automation Center, Columbus
Lines: 35

From article <8900@ncar.ucar.edu>, by tparker@bierstadt.scd.ucar.edu (Tom Parker):
> 
> I'm having trouble finding a way to read a line of a file in the C-shell.
> 
> For instance, I would like my script to read the first line of a file,
> process it, then read the second line, process it, etc.
> 
> I tried something like      foreach line(`cat file`)
> but this seems to process the entire file, a word at a time.

Before doing the "foreach", set the InterField Separator (variable name IFS)
to  a newline character.  The default for IFS is whitespace that includes
blanks.  The default would give you to get one "word" at a time.

When you do this, "line" may include blanks and can sometimes cause syntax
errors because the blanks can be interpreted as separators between command
line arguments.  Example (Bourne syntax):

	IFS='
'			# newline enclosed between single quotes
	for line in `cat file`
	do
	if test $line = ""; then ....

may cause a syntax error in the test command if $line contains whitespace.
However, the statement

	if test "$line" = ""; then ....

will not since the quotes delimit a single argument to the test command.
-- 
Bob Fisher
US Defense Logistics Agency Systems Automation Center
DSAC-TOL, Box 1605, Columbus, OH 43216-5002     614-238-9071 (AV 850-9071)
bfisher@dsac.dla.mil		osu-cis!dsacg1!bfisher