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From: Melvin on 23 Feb 2010 01:33
Hi,

I was trying to compare if the last lline of a file is $end in tcsh.

I tried this:
######################
set string1 = `cat file|tail -1`
set string2 = "\$end"

if (string1 != string2) then
echo "Not matching"
endif
#####################

But shell doesn't allow to compare "$end"[I tries adding the \ to
remove the effect of "$" in $end]
Error: $end: undefined variable

Thanks in Advance
Shell Baby




From: David W. Hodgins on 23 Feb 2010 02:01
On Tue, 23 Feb 2010 01:33:34 -0500, Melvin <whereismelvin(a)gmail.com> wrote:

> I was trying to compare if the last lline of a file is $end in tcsh.
> I tried this:
> ######################
> set string1 = `cat file|tail -1`
> set string2 = "\$end"
>
> if (string1 != string2) then
I haven't tested it, by try
if ("string1" != "string2") then

Basic rule. Unless you have a reason not to, always double quote
all variables.

Regards, Dave Hodgins

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From: Melvin on 23 Feb 2010 02:19
Hi Dave,

I tried wih the double qoutes; but still the same error [end:
undefined variable]

Is there anyway that the keyword interpretation for $end can by
bypassed...Guess somehow "\" is not being taken?

Thanks
Shell Baby
From: Melvin on 23 Feb 2010 02:31
Hi,

The undefined Variable problem is solved.

Sln: set string2 = "\$\end"

But now string2 assignment results in an error "VARIABLE NAME MUST
CONTAIN ALPHANUMERIC CHARACTERS"

Any Suggestions
From: Barry Margolin on 23 Feb 2010 03:33
In article
<1ebd935b-81be-47b7-ad73-382e15a22f5b(a)z19g2000yqk.googlegroups.com>,
Melvin <whereismelvin(a)gmail.com> wrote:

> Hi,
>
> I was trying to compare if the last lline of a file is $end in tcsh.
>
> I tried this:
> ######################
> set string1 = `cat file|tail -1`
> set string2 = "\$end"
>
> if (string1 != string2) then
> echo "Not matching"
> endif
> #####################
>
> But shell doesn't allow to compare "$end"[I tries adding the \ to
> remove the effect of "$" in $end]
> Error: $end: undefined variable
>
> Thanks in Advance
> Shell Baby

Use single quotes instead of double quotes, and then it won't try to
expand variables:

set string2 = '$end'

Also, the if statement should be:

if ( "$string1" != "$string2" ) then

Variables aren't expanded if you don't use the $ prefix.

--
Barry Margolin, barmar(a)alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***
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