remove specific data from a line

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

Hello, I need help with Perl problem that I'm having. I just start with Perl and don't have enough knowledge to fix problem quick.
I have file with lines in that look like this

myword myobject,option2,option3 word word word
[download]

The words delimited by comma after myobject are optional. There may or may not be these optional words in each line.
myword if present always is at begin of line and if there would always be follow by at least one space then another word (and then possible optional words).
I find the lines in the file that begin with myword like this


while (my $line=<DATA>) {
     if $line =~ /^myword\s+/ {
           work on line;
     }
}
[download]

I want to strip "myword myobject,option1,option2" from line but not know how do this e.g. something like

   if $line =~ /^myword\s+/ {
     $line =~ s/^myword myobject,options//g
    }
[download]

I knows what first few characters of myword will be but not what myobject will be (except it's always a word).
How does I do this ? ciao

Comment on remove specific data from a line Select or Download Code

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Re: remove specific data from a line by Roy Johnson (Monsignor) on Feb 02, 2006 at 15:36 UTC
I think you want: `$line =~ s/^myword \S+//; # strip myword, a space, and any stretch of +non-spaces` [download] Update: After seeing your clarification, I see that you could have spaces in the comma-separated list. So you'd want: `$line =~ s/^ #strip, from the beginning of the string, myword\s+ #myword, followed by whitespace \S+ #followed by non-whitespace (?:,\s\S+) #followed by any number of comma, optional w +hitespace, non-whitespace //x; # update: two slashes are needed here` [download] Caution: Contents may have been coded under pressure.	[reply] [d/l] [select]
Re^2: remove specific data from a line by Anonymous Monk on Feb 03, 2006 at 09:54 UTC
This one nearly work but not handle this line `abcefgh qwerty, asdfg yuio jklh` [download] It print out `asdfg yuio jklh` [download] I had to add extra slash to your code like this `$line =~ s/^abc\w+\s+\S+(?:,\s\S+)//x;` [download] otherwise got errors. I hope this was what you mean. I try to change your code to handle last line which don't leave just `yuio jklh`. How do I fix this ? Thank you for answer so far , it show me how much flexible Perl is	[reply] [d/l] [select]
Re^3: remove specific data from a line by Roy Johnson (Monsignor) on Feb 03, 2006 at 18:29 UTC
I forgot to substitute the first word back in. `$line =~ s/^(abc)\w+\s+\S+(?:,\s\S+)/$1/x;` [download] should give you what you want. You were right about the missing slash. Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re: remove specific data from a line by idle (Friar) on Feb 02, 2006 at 15:26 UTC
So you wanna remove the string if it start with myword? Try this: `if $line =~ /^myword.$/ { $line =~ s/$&//g }` [download] Updated. Oh I see you need to remove the line until the last option. Heres the code: `if $line =~ /(^myword.option\d+\s+).*$/ { $line =~ s/$1//g }` [download]	[reply] [d/l] [select]
Re^2: remove specific data from a line by Anonymous Monk on Feb 02, 2006 at 15:36 UTC
I not explain too good sorry. Let me try eloborate. String could look like this `abc123 qwerty,asdfg,zxcvb yuio jklh` [download] or like this `abc987 qwerty yuio jklh` [download] or this `abcefgh qwerty, asdfg yuio jklh` [download] So I want to end up with same string from all examples above. It should end up like this `yuio jklh` [download] Hope this make it bit clearer, sorry for confuse my english not so good	[reply] [d/l] [select]
Re^3: remove specific data from a line by graff (Chancellor) on Feb 03, 2006 at 03:17 UTC
Given those examples, there might be a few ways to do this -- either try to match from the start of the string: `s/abc\w+\s+\w+(?:, \w+)\s+//; # match and remove unwanted initial co +ntent` [download] or else just look for what you want to keep at the end: `s/.\s(\w+\s+\w+)$/$1/; # match desired end content and remove everyt +hing before it` [download] And of course, if you know in advance how those last two tokens are spelled, you could even use rindex() and substr(): `$_ = substr( $_, rindex( $_, 'yuio jklh' ));` [download]	[reply] [d/l] [select]
Re^4: remove specific data from a line by Anonymous Monk on Feb 03, 2006 at 10:06 UTC