Delete strings

sandy1028 has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: Delete strings by almut (Canon) on Apr 10, 2009 at 08:09 UTC
`perl -i -ne 'print if $end_del \|\|= /1\.0/' file` [download] `/1\.0/` does a substring match; if you want to stop deleting only when the line contains nothing but "1.0", either use `/^1\.0$/`, or `$_ eq "1.0\n"`.	[reply] [d/l] [select]
Re^2: Delete strings by jwkrahn (Abbot) on Apr 10, 2009 at 16:00 UTC
Another way to do that: `perl -i -ne 'print if /1\.0/ .. eof' file` [download]	[reply] [d/l]
Re^2: Delete strings by zashwing (Initiate) on Apr 10, 2009 at 15:51 UTC
What's with the idea you have to write the solution in a single line of code? This can be done easily with a few lines of code, why write it in a single line? Are you running with 8MB of ram or something? 1. Open the file IO in read write mode. 2. Read the file into an array. 3. Set up a good old fashioned boolean $foundString 4. Traverse the array til the boolean is true printing stuff to the file. 5. Boolean is true close the file..DONE.	[reply]
Re^3: Delete strings by almut (Canon) on Apr 10, 2009 at 16:55 UTC
... why write it in a single line? Why not? I never said you have to... Feel free to write as many lines as makes you feel comfortable. I just happen to like one-liners for tasks like these — which doesn't imply anyone else would have to like or use them, too. Yet others like golfing. Just for the fun of it...	[reply]
Re: Delete strings by ikegami (Patriarch) on Apr 10, 2009 at 08:13 UTC
You can't delete lines from a file. You can copy a file while doing modifications to what is copied. So after opening the two files, While the source hasn't been exhausted, Read a line from the source. If line contains '1.0' or such a line was already found, Print the line to the destination. As a one-liner: `perl -ne"print if $f \|\|= /1\.0/" infile >outfile` [download] or in-place: `perl -i.bak -ne"print if $f \|\|= /1\.0/" file` [download] Update: The above were for the Windows Command shell. Below are adaptations for `bash`: `perl -ne'print if $f \|\|= /1\.0/' infile >outfile` [download] or in-place: `perl -i~ -ne'print if $f \|\|= /1\.0/' file` [download]	[reply] [d/l] [select]
Re^2: Delete strings by vinoth.ree (Monsignor) on Apr 10, 2009 at 08:51 UTC
Your code is not working for me! Vinoth,G	[reply]
Re^3: Delete strings by lakshmananindia (Chaplain) on Apr 10, 2009 at 09:05 UTC
Try executing as below `perl -i.bak -ne"print if "\$f" \|\|= /1\.0/" file` [download] In unix the shell interprets the $f. So you were unable to execute. --Lakshmanan G. The great pleasure in my life is doing what people say you cannot do.	[reply] [d/l]
Re^3: Delete strings by almut (Canon) on Apr 10, 2009 at 08:57 UTC
Are you on Unix or on Windows? On Unix, the shell would interpolate `$f` in double quoted strings, so it's usually easier to use single quotes for Perl one-liners... OTOH, on Windows you'd have to use double quotes, as single quotes don't work (as quotes) with the standard shell...	[reply] [d/l]
Re^4: Delete strings by vinoth.ree (Monsignor) on Apr 10, 2009 at 14:29 UTC
Re^3: Delete strings by ww (Archbishop) on Apr 10, 2009 at 12:25 UTC
ree: your reply is not an error message for me. Update: identified node to which this is a response.	[reply]


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