Re: dynamic zcat and grep

I believe this line:

open INFILE, 'zcat $filename  |' or print "ERROR - Could not open $fil
+ename";
[download]

is running afoul of Perl's quoting convention; single quotes don't interpolate variable values. Try replacing the single quotes with double quotes.

emc

" The most likely way for the world to be destroyed, most experts agree, is by accident. That's where we come in; we're computer professionals. We cause accidents."
—Nathaniel S. Borenstein

Comment on Re: dynamic zcat and grep Download Code

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Re^2: dynamic zcat and grep by clmcshque (Initiate) on Mar 21, 2006 at 22:38 UTC
Thanks for the reply. I've tried many different encarnations of that line: `open(INFILE, "zcat $filename \|") open(INFILE, 'zcat $filename \|') open INFILE, "zcat $filename \|"` [download] all with the similar results. `zcat: compressed data not read from a terminal. Use -f to force decomp +ression. For help, type: zcat -h` [download]	[reply] [d/l] [select]
Re^3: dynamic zcat and grep by swampyankee (Parson) on Mar 22, 2006 at 03:29 UTC
Sorry my help was not helpful. I've looked at the docs for zcat (well, OpenBSD's docs for zcat) and it seems that your first and third choices should work: zcat unzips the input file to STDOUT. When I get a chance (probably about 24 hours from now), I'll muck about on by OpenBSD box to see if I can replicate your results. emc " The most likely way for the world to be destroyed, most experts agree, is by accident. That's where we come in; we're computer professionals. We cause accidents." —Nathaniel S. Borenstein	[reply]
Re^3: dynamic zcat and grep by johngg (Canon) on Mar 22, 2006 at 11:23 UTC
Can you use your zcat in a pipe on the command line? Like `% cat file.gz \| zcat \| less` [download] This works on Solaris but if it doesn't work for you it could be that your zcat demands the presence of a terminal as implied by your results. Cheers, JohnGG	[reply] [d/l]
Re^4: dynamic zcat and grep by clmcshque (Initiate) on Mar 22, 2006 at 17:08 UTC
On the command line I use: `$ zcat file.gz \| grep ...` [download] Which works just fine. Is that the same?	[reply] [d/l]
Re^2: dynamic zcat and grep by Anonymous Monk on Oct 03, 2012 at 02:13 UTC
This is an old thread but this answer may prove useful to others, I had a similar problem with a command similar to `zcat -c test.gz \| pythonscript.py > test.out` being called within a makefile, it had the same error as mentioned in this thread. I ended up changing it to `cat test.gz \| zcat -c \| pythonscript.py > test.out` Regards Brad	[reply] [d/l] [select]

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