[gentoo-user] Need help with a regex
Regexs are not my strong point! I am trying to get a list of service scripts that provide virtual services. Each such script contains a line like: provide dns i.e. the line starts with one or more spaces, followed by the text provide, followed by one or more spaces and a single word. i have come up with: grep -e ^\s+provide\s+\w /etc/init.d but, as usual, nothing is matched. What am I doing wrong? TIA -Robin -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Sat, May 24, 2008 at 11:22 AM, Robin Atwood [EMAIL PROTECTED] wrote: Regexs are not my strong point! I am trying to get a list of service scripts that provide virtual services. Each such script contains a line like: provide dns i.e. the line starts with one or more spaces, followed by the text provide, followed by one or more spaces and a single word. i have come up with: grep -e ^\s+provide\s+\w /etc/init.d Right now you are saying: match one or more spaces in the begining followed by provide followed by one or more spaces followed by *one* word followed by one space and followed by /etc/init.d I think you mean: grep -e ^\s+provide\s+\w+ /etc/init.d but, as usual, nothing is matched. What am I doing wrong? TIA -Robin -- gentoo-user@lists.gentoo.org mailing list -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Sat, May 24, 2008 at 11:32 AM, Andrey Falko [EMAIL PROTECTED] wrote: On Sat, May 24, 2008 at 11:22 AM, Robin Atwood [EMAIL PROTECTED] wrote: Regexs are not my strong point! I am trying to get a list of service scripts that provide virtual services. Each such script contains a line like: provide dns i.e. the line starts with one or more spaces, followed by the text provide, followed by one or more spaces and a single word. i have come up with: grep -e ^\s+provide\s+\w /etc/init.d Right now you are saying: match one or more spaces in the begining followed by provide followed by one or more spaces followed by *one* word followed by one space and followed by /etc/init.d I think you mean: grep -e ^\s+provide\s+\w+ /etc/init.d but, as usual, nothing is matched. What am I doing wrong? I see your mistake\w means alphanumeric character, not word. TIA -Robin -- gentoo-user@lists.gentoo.org mailing list -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, 17:22, Robin Atwood wrote:
Regexs are not my strong point! I am trying to get a list of service
scripts that provide virtual services. Each such script contains a
line like:
provide dns
i.e. the line starts with one or more spaces, followed by the text
provide, followed by one or more spaces and a single word. i have
come up with:
grep -e ^\s+provide\s+\w /etc/init.d
but, as usual, nothing is matched. What am I doing wrong?
On my system, no initscript has the line provide dns in it, so it might
be possible that you don't have any file with that line.
That said, you should use -r, and you don't need the -e switch:
grep -r '^[[:space:]]\{1,\}provide[[:space:]]\{1,\}dns' /etc/init.d
or, perhaps clearer
grep -rE '^[[:space:]]+provide[[:space:]]+dns' /etc/init.d
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Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Andrey Falko wrote: On Sat, May 24, 2008 at 11:32 AM, Andrey Falko [EMAIL PROTECTED] wrote: On Sat, May 24, 2008 at 11:22 AM, Robin Atwood [EMAIL PROTECTED] wrote: Regexs are not my strong point! I am trying to get a list of service scripts that provide virtual services. Each such script contains a line like: provide dns i.e. the line starts with one or more spaces, followed by the text provide, followed by one or more spaces and a single word. i have come up with: grep -e ^\s+provide\s+\w /etc/init.d Right now you are saying: match one or more spaces in the begining followed by provide followed by one or more spaces followed by *one* word followed by one space and followed by /etc/init.d I think you mean: grep -e ^\s+provide\s+\w+ /etc/init.d but, as usual, nothing is matched. What am I doing wrong? I see your mistake\w means alphanumeric character, not word. I had just realised that myself. However, it still doesn't work. :( Thanks for trying, though. -Robin -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Robin Atwood wrote: Regexs are not my strong point! I am trying to get a list of service scripts that provide virtual services. Each such script contains a line like: provide dns i.e. the line starts with one or more spaces, followed by the text provide, followed by one or more spaces and a single word. i have come up with: grep -e ^\s+provide\s+\w /etc/init.d but, as usual, nothing is matched. What am I doing wrong? grep -e is not the same thing as egrep or grep -E, and I never managed to get \s to work as a synonym for [[:space:]] Plus you need a proper file glob i your file spec Try: egrep '^[[:space:]]+provide[[:space:]]+\w' /etc/init.d/* As in: [EMAIL PROTECTED] /etc/init.d $ egrep '^[[:space:]]+provide[[:space:]]+\w' /etc/init.d/* /etc/init.d/courier-authlib:provide authdaemond /etc/init.d/hwclock:provide clock /etc/init.d/net.eth0: provide net /etc/init.d/net.lo: provide net /etc/init.d/net.lo.openrc.bak: provide net /etc/init.d/net.wlan0: provide net /etc/init.d/postfix:provide mta /etc/init.d/shorewall: provide firewall /etc/init.d/syslog-ng: provide logger /etc/init.d/vixie-cron: provide cron [EMAIL PROTECTED] /etc/init.d $ grep -E '^[[:space:]]+provide[[:space:]]+\w' /etc/init.d/* /etc/init.d/courier-authlib:provide authdaemond /etc/init.d/hwclock:provide clock /etc/init.d/net.eth0: provide net /etc/init.d/net.lo: provide net /etc/init.d/net.lo.openrc.bak: provide net /etc/init.d/net.wlan0: provide net /etc/init.d/postfix:provide mta /etc/init.d/shorewall: provide firewall /etc/init.d/syslog-ng: provide logger /etc/init.d/vixie-cron: provide cron [EMAIL PROTECTED] /etc/init.d $ grep -e '^[[:space:]]+provide[[:space:]]+\w' /etc/init.d/* [EMAIL PROTECTED] /etc/init.d $ -- Alan McKinnon alan dot mckinnon at gmail dot com -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Etaoin Shrdlu wrote:
On Saturday 24 May 2008, 17:22, Robin Atwood wrote:
Regexs are not my strong point! I am trying to get a list of service
scripts that provide virtual services. Each such script contains a
line like:
provide dns
i.e. the line starts with one or more spaces, followed by the text
provide, followed by one or more spaces and a single word. i have
come up with:
grep -e ^\s+provide\s+\w /etc/init.d
but, as usual, nothing is matched. What am I doing wrong?
On my system, no initscript has the line provide dns in it, so it might
be possible that you don't have any file with that line.
That said, you should use -r, and you don't need the -e switch:
grep -r '^[[:space:]]\{1,\}provide[[:space:]]\{1,\}dns' /etc/init.d
or, perhaps clearer
grep -rE '^[[:space:]]+provide[[:space:]]+dns' /etc/init.d
I am looking for all the scripts with lines like provide xxx, not just the
dns service. That said, your solution did the trick! I amended the expression
to:
grep -rE '^[[:space:]]+provide[[:space:]]+\w+' /etc/init.d
and got what I was after. But why does [[:space:]]+ work and \s+ fail?
Cheers
-Robin
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tel/fax: +66 2252 1438
mobile: +66 851 322487
MSN:[EMAIL PROTECTED]
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Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Alan McKinnon wrote: grep -e is not the same thing as egrep or grep -E, and I never managed to get \s to work as a synonym for [[:space:]] I was wondering about that! Plus you need a proper file glob i your file spec That was a typo in my post. Try: egrep '^[[:space:]]+provide[[:space:]]+\w' /etc/init.d/* Thanks, I am in business now. Cheers -Robin -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Robin Atwood wrote: But why does [[:space:]]+ work and \s+ fail? Apparently because \s is not a synonym for [[:space:]] I've heard this one before but never got it to work and never seen it in writing. Do you have a reference for where you read it? -- Alan McKinnon alan dot mckinnon at gmail dot com -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
Robin Atwood wrote: grep -e ^\s+provide\s+\w /etc/init.d but, as usual, nothing is matched. What am I doing wrong? You have to use back slashed versions of metacharacters. Following how would do that: $ grep -e '^[[:space:]]\+provide[[:space:]]\+[a-z]\+' /etc/init.d/* /etc/init.d/syslog-ng: provide logger /etc/init.d/vixie-cron: provide cron W. Canis signature.asc Description: OpenPGP digital signature
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Alan McKinnon wrote: On Saturday 24 May 2008, Robin Atwood wrote: But why does [[:space:]]+ work and \s+ fail? Apparently because \s is not a synonym for [[:space:]] Here for a start: http://www.regular-expressions.info/charclass.html#shorthand and also http://doc.trolltech.com/3.3/qregexp.html#characters-and-abbreviations-for-sets-of-characters Is it a Perl thing? Probably! http://www.troubleshooters.com/codecorn/littperl/perlreg.htm#DoingStringComparisons -Robin -- -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
On Saturday 24 May 2008, Robin Atwood wrote: On Saturday 24 May 2008, Alan McKinnon wrote: On Saturday 24 May 2008, Robin Atwood wrote: But why does [[:space:]]+ work and \s+ fail? Apparently because \s is not a synonym for [[:space:]] Here for a start: http://www.regular-expressions.info/charclass.html#shorthand and also http://doc.trolltech.com/3.3/qregexp.html#characters-and-abbreviation s-for-sets-of-characters Is it a Perl thing? Probably! http://www.troubleshooters.com/codecorn/littperl/perlreg.htm#DoingStr ingComparisons Ah yes, it's the old: grep/sed/awk/vi/perl-implement-regexes-identically-except-when-they-don't thing again! -- Alan McKinnon alan dot mckinnon at gmail dot com -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] Need help with a regex
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Robin Atwood wrote: grep -e ^\s+provide\s+\w /etc/init.d but, as usual, nothing is matched. What am I doing wrong? You have to use back slashed versions of meta characters. Following how would do that: $ grep -e '^[[:space:]]\+provide[[:space:]]\+[a-z]\+' /etc/init.d/* /etc/init.d/syslog-ng: provide logger /etc/init.d/vixie-cron: provide cron W. Canis -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkg4dvkACgkQKT9zBKF0twURhwCZAQ/vK1la7X0mTuA2yTyWavqc rEIAn1yr+ytPejcRXMr/d6f/Wkg4SgSc =NQmh -END PGP SIGNATURE- -- gentoo-user@lists.gentoo.org mailing list
