sort lines in a txt file

[cassius]

Hi.
I've formatted a long txt file with 300 lines, where each line consists of comma separated values with 60 fields for each line.

How could i sort all the lines with the second(counting from zero)element in each line as the "sort argument"

Example:
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30025", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30020", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30025", ".....", ......

I would like to write a function that sorts(and writes to a new file) in this order:
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30000", ".....", ......
" ", "310805", "30020", ".....", ......
" ", "310805", "30025", ".....", ......
" ", "310805", "30025", ".....", ......

Help would be much appreciated.

[Weedpacket]

If you're capable of looking at two lines and working out which one should go before the other, then [man]usort[/man] would do the job.

[cassius]

Yes, i understand. Tnx. But my question is rather how to compare all the lines in a file and to sort them right before i write to a new file?

Any example(s) to help me getting started ?

[Weedpacket]

You'll have to in read the entire file, sort it (using [man]usort[/man]) and then write the entire file out again.

You need to read the entire file before you sort it, of course, because for all the program knows, the very first line in the sorted file might be the very last line in the unsorted file.