Re: replace field

Your algorithm won't work because:

You are opening the file in append mode which starts out with the file pointer at the end of the file so the while loop has nothing to read.
If you didn't use append mode then you have the problem that reads and writes use the same file pointer so you read from one record and then write to the next record leaving the original record untouched.
If you fixed that then you still have the problem that $newval=$val+1; may cause the $val field go from one digit to two digits or two digits to three digits etc. causing you to write one byte into the next field.

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Re^2: replace field by Anonymous Monk on Jul 31, 2009 at 13:21 UTC
I tried to do +> but it seems to empty the file. About $val+1, according to the program logic the digit there will always be single digit, so there is no problem of additional bit. So the only problem now, is to open the file and grep a key and then replace the 2nd field. So anything else I can do now...?	[reply]
Re^3: replace field by BioLion (Curate) on Jul 31, 2009 at 15:54 UTC
Maybe you could use Tie::File ? You can process the file as an array and modify the lines in place using ikegami's suggestion. HTH! Just a something something...	[reply] [d/l]
Re^3: replace field by Anonymous Monk on Jul 31, 2009 at 13:32 UTC
`>` means CLOBBER the file (ie delete, recreate)	[reply] [d/l]