Simple perl one-liner for transforming text files

m5m5m has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Simple perl one-liner for transforming text files by BrowserUk (Patriarch) on Mar 05, 2003 at 20:58 UTC
`perl -n000 -e" s[name: ([^\n]+)\ndate: ([^\n]+)\n.*][$1 $2]; chomp; pr +int qq[$_\n]; " <file >newfile` [download] Use 's instead of "s on linux etc. Examine what is said, not who speaks. 1) When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. 2) The only way of discovering the limits of the possible is to venture a little way past them into the impossible 3) Any sufficiently advanced technology is indistinguishable from magic. Arthur C. Clarke.	[reply] [d/l]
Re: Re: Simple perl one-liner for transforming text files by jdporter (Chancellor) on Mar 06, 2003 at 06:22 UTC
Way too verbose! ;-) `perl -n000 -pe "$_=qq(@{{/(.?): (.)/g}}{name,date}\n)"` [download] jdporter The 6th Rule of Perl Club is -- There is no Rule #6.	[reply] [d/l]
Re: Re: Re: Simple perl one-liner for transforming text files by BrowserUk (Patriarch) on Mar 06, 2003 at 06:48 UTC
Sorry, I wasn't wearing my golf shoes:^) jdporter++. I physically applauded that once I stared at it long enough to work out how the hell it worked. Examine what is said, not who speaks. 1) When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. 2) The only way of discovering the limits of the possible is to venture a little way past them into the impossible 3) Any sufficiently advanced technology is indistinguishable from magic. Arthur C. Clarke.	[reply]
Re: Re: Simple perl one-liner for transforming text files by m5m5m (Initiate) on Mar 05, 2003 at 21:09 UTC
Very cool. After a bit of reading, I think I understand what you are doing... Does not seem to work for me (prints out every line) yet, maybe I mistyped something... Let me go through it again... Thanks !	[reply]
Re: Re: Re: Simple perl one-liner for transforming text files by BrowserUk (Patriarch) on Mar 05, 2003 at 21:18 UTC
A quick example of it in operation. C:\test>type junk name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah C:\test>perl -n000 -e" s[name: ([^\n]+)\ndate: ([^\n]+)\n.*][$1 $2]; c +homp; print qq[$_\n]; " <junk url1.domain1.com 2004/2/1 url2.domain5.org 2004/3/12 url1.domain1.com 2004/2/1 url2.domain5.org 2004/3/12 url1.domain1.com 2004/2/1 url2.domain5.org 2004/3/12 url1.domain1.com 2004/2/1 url2.domain5.org 2004/3/12 C:\test> [download] Examine what is said, not who speaks. 1) When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. 2) The only way of discovering the limits of the possible is to venture a little way past them into the impossible 3) Any sufficiently advanced technology is indistinguishable from magic. Arthur C. Clarke.	[reply] [d/l]
Re: Simple perl one-liner for transforming text files by pfaut (Priest) on Mar 05, 2003 at 20:56 UTC
Not quite one line, but... You're 'records' are separated by a ~~new~~ blank line so set the input record separator ($/) to a pair of newlines. Then split each record on newlines and take the part after the colon for the fields you want. `#!/usr/bin/perl -w use strict; $/ = "\n\n"; while (<DATA>) { my @wanted = map { (split(/:\s+/))[1] } (split /\n/)[0..1]; print "@wanted\n"; } __DATA__ name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah` [download] `--- print map { my ($m)=1<<hex($_)&11?' ':''; $m.=substr('AHJPacehklnorstu',hex($_),1) } split //,'2fde0abe76c36c914586c';` [download]	[reply] [d/l] [select]
Re: Simple perl one-liner for transforming text files (JAWTDI) by tye (Sage) on Mar 05, 2003 at 21:37 UTC
`perl -ne 'print ++$n,". $1 " if /^name:\s(.)/; print $1,$/ if /^date +:\s(.)/'` [download] or, for Win32: `perl -ne "print ++$n,qq(. $1 ) if /^name:\s(.)/; print $1,$/ if /^da +te:\s(.)/"` [download] - tye	[reply] [d/l] [select]
Re: Simple perl one-liner for transforming text files by Enlil (Parson) on Mar 05, 2003 at 21:05 UTC
heres my attempt: `perl -n0e 'while (/name: (.)\ndate: (.)/g){$cnt++;print "$cnt. $1 $2 +\n"}' <FILE>` [download] -enlil	[reply] [d/l]
Re: Simple perl one-liner for transforming text files by hiseldl (Priest) on Mar 06, 2003 at 03:23 UTC
Here's another version. When running one-liners it is extremely useful to learn the command line operators. Here's a short breakdown: use `-aF:` to split on the ':' and store it in `@F` use `-l` to automatically chomp $/ use `-0` (minus zero) to specify the input record separator ($/) as the null character use `-n` to loop over every line of input use `-e` to run the script following it the first expression prints the counter if the line contains name the second expression prints the right side of the ':' if the line contains name or date the last expression prints a newline (or record separator) if the line contains date `perl -al0nF: -e 'print /name/&&++$x,/name\|date/&&$F[1],/date/&&$/' data.txt` the data file contains: `name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/2 unwanted info: blah blah blah name: url3.domain1.com date: 2004/2/3 unwanted info: blah blah blah name: url4.domain5.org date: 2004/3/4 unwanted info: blah blah blah name: url5.domain1.com date: 2004/2/5 unwanted info: blah blah blah name: url6.domain5.org date: 2004/3/6 unwanted info: blah blah blah` [download] and here are the results of running the script: `1 url1.domain1.com 2004/2/1 2 url2.domain5.org 2004/3/2 3 url3.domain1.com 2004/2/3 4 url4.domain5.org 2004/3/4 5 url5.domain1.com 2004/2/5 6 url6.domain5.org 2004/3/6` [download] Change all the ' into " to run on win32 HTH. -- hiseldl What time is it? It's Camel Time!	[reply] [d/l] [select]
Re: Re: Simple perl one-liner for transforming text files by DaveH (Monk) on Mar 06, 2003 at 09:09 UTC
Do sick minds think alike? It would seem we came up with very similar answers! Cheers, -- Dave :-) $q=[split+qr,,,q,~swmi,.$,],+s.$.Em~w^,,.,s,.,$&&$$q[pos],eg,print	[reply]
Re: Simple perl one-liner for transforming text files by zengargoyle (Deacon) on Mar 06, 2003 at 06:30 UTC
`perl -000ne 'print"$.. @{[(split)[1,3]]}\n"' data.txt` [download]	[reply] [d/l]
Re: Simple perl one-liner for transforming text files by OM_Zen (Scribe) on Mar 06, 2003 at 04:48 UTC
Hi , The regular expression pre-defined variables can be the ones to be for this `while(<Fnm>){chomp;if($_=~/^name:\s+/){$cnt++;print "$cnt\. $'";}elsif +($_=~/^date:\s+/){print " $'\n";}} __DATA__ name: url1.domain1.com date: 2004/2/1 unwanted info: blah blah blah name: url2.domain5.org date: 2004/3/12 unwanted info: blah blah blah __END__ 1. url1.domain1.com 2004/2/1 2. url2.domain5.org 2004/3/12` [download]	[reply] [d/l]
Re: Simple perl one-liner for transforming text files by DaveH (Monk) on Mar 06, 2003 at 01:08 UTC
Hi. Should this move to Obfuscated Code? :-) `perl -F: -al0ne '$i\|\|=1;/^n/&&print$i;!/^u/&&print$F[1];/^$/&&$i++&&pr +int$/'` [download] I don't think it meets the "simple" requirement, but it is mostly on one line... ;-) Here is what B::Deparse makes of it though, for reference. `LINE: while (defined($_ = <ARGV>)) { chomp $_; @F = split(/:/, $_, 0); $i \|\|= 1; print $i if /^n/; print $F[1] if not /^u/; print $/ if /^$/ and $i++; }` [download] I'm not sure if the preceeding number is a requirement or not. Without the number prefix, I can get down to: `perl '-F: ' -al0ne '!/^u/&&print qq($F[1] );/^$/&&print$/'` [download] (To run on Win32, change all the ' into " - it should still work.) Hope that helps. Cheers, -- Dave :-) $q=[split+qr,,,q,~swmi,.$,],+s.$.Em~w^,,.,s,.,$&&$$q[pos],eg,print	[reply] [d/l] [select]


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