Simple question for all of you python gurus

[Sean Berry]

I am writing a little script to grep through a really long list of files and
look for a certain phrase.

I wanted to do something like this.

li = os.popen("/usr/bin/grep -i %s /home/%s/.tmda/pending" %(phrase,userid)
lis = li.readlines()
blah blah blah...

but even if I run this from the command line I get an error saying the
argument list is too long.

However, if I cd to /home/userid/.tmda/pending and then run the grep from
within the directory... it works great.

so I tried to do something like this
os.system("cd /home/%s/.tmda/pending" %userid)
li = os.popen("/usr/bin/grep -i %s" %phase)
lis = lis.readlines()

But since cd is a shell command, it does not seem to work either.

How can I do this?
Thanks in advance for answering this seemingly easy question.

[Diez B. Roggisch]

> How can I do this?

Thanks in advance for answering this seemingly easy question.

You're code might work if you use os.chdir to change the current working
directory.

Another that works on the command-line (and thus for your script) is to use
xargs with -l<num>, e.g.:

find / | xargs -l 10 grep -i foo

xargs then will invoke grep in batches of ten.

--
Regards,

Diez B. Roggisch

[Cameron Laird]

In article <NYu%b.12366$qL1.145@fed1read02>,
Sean Berry <se********@cox.net> wrote:

[Sean Berry]

Thanks to you both.

os.chdir ... I knew it was something simple. Sorry for the wasted
bandwidth.

Cameron Laird <cl****@lairds.com> wrote in message
news:10*************@corp.supernews.com...

In article <NYu%b.12366$qL1.145@fed1read02>,
Sean Berry <se********@cox.net> wrote:
.
.
.

so I tried to do something like this
os.system("cd /home/%s/.tmda/pending" %userid)
li = os.popen("/usr/bin/grep -i %s" %phase)
lis = lis.readlines()

But since cd is a shell command, it does not seem to work either.

How can I do this?

.
.
.
import os

os.chdir("/home/%s/.tmda/pending" % userid)
li = os.popen(...
--

Cameron Laird <cl****@phaseit.net>
Business: http://www.Phaseit.net

[Jeremy Sanders]

On Thu, 26 Feb 2004 23:14:33 +0000, Cameron Laird wrote:

os.chdir("/home/%s/.tmda/pending" % userid)
li = os.popen(...

Wouldn't something like this also work?

li = os.popen('/bin/sh -c "cd /home/%s; /usr/bin/grep -i %s blah"')

This has the advantage that the current directory of the Python program
doesn't change.

Jeremy

[Cameron Laird]

In article <pa****************************@jeremysanders.net> ,
Jeremy Sanders <je*************@jeremysanders.net> wrote:

On Thu, 26 Feb 2004 23:14:33 +0000, Cameron Laird wrote:

os.chdir("/home/%s/.tmda/pending" % userid)
li = os.popen(...

Wouldn't something like this also work?

li = os.popen('/bin/sh -c "cd /home/%s; /usr/bin/grep -i %s blah"')

This has the advantage that the current directory of the Python program
doesn't change.