sorting question

[dictum9]

I want to sort output by the certain column, ie. 4th column. From the man page, the necessary option seems to be -k, so that

cat file | sort -k 5

It sorts it in a different way but it doesn't work. Neither does

cat file | sort -k 5.3

[A. Clay Stephenson · Accepted solution]

Several things could be wrong. 1) You haven't specified what the separator charactor is so that is the 5th field may not be what sort thinks is the 5th field. Ialso you may need a type specifier such as -k 5n,5 to force numeric comparisons rather than lexical comparisons. For example, if 'n' were not used (and assumming this us the 5th field)
1
2
3
10
20
100

would actually be sorted as

1
10
100
2
20
3

[Patrick Wallek]

Can you show us a sample of the file you want to sort? Just a few lines will do. This may help in figuring out how to get it sorted.

[Sung Oh]

if you are sorting by 4th column, you should use

cat file | sort -k 4

if this still does not work can you print the outout to here?

Sung

[Ivan Ferreira]

I just use:

cat file | sort +3

Because the columns starts at 0. If you are doinig numeric sorting, use -n, like this:

cat file | sort +3 -nb

[dictum9]

-n flag does the trick, thanks.

( As usual, the man page is cryptic )

[Arturo Galbiati]

Hi,
why not sort -n +3 file avoiding cat?
HTH,
Art