how can I sort a string like, for instance
"1.3.2 1.3.1 1.2.3 1.1.1.5"
to
"1.1.1.5 1.2.3 1.3.1 1.3.2"
So I don't know how many numbers the version consists of and I don't know how many versions there are in the string.
How to solve this?
Thanks
This is one of the few instances where NOT quoting a variable is useful.
$ string="1.3.2 1.3.1 1.2.3 1.1.1.5"
$ printf "%s\n" $string | sort -V
1.1.1.5
1.2.3
1.3.1
1.3.2
This uses GNU sort's -V aka --version-sort option to sort the numbers.
You can store that back into a variable, even the same variable ($string):
$ string=$(printf "%s\n" $string | sort -V)
$ echo $string
1.1.1.5 1.2.3 1.3.1 1.3.2
or an array:
$ array=( $(printf "%s\n" $string | sort -V) )
$ typeset -p array
declare -a array=([0]="1.1.1.5" [1]="1.2.3" [2]="1.3.1" [3]="1.3.2")
BTW, you should almost certainly be using an array rather than a simple string with white-space separating multiple different values. The only real reason not to is if you're using a shell (like ash) that doesn't support arrays.
e.g.
$ array=( 1.3.2 1.3.1 1.2.3 1.1.1.5 )
$ typeset -p array
declare -a array=([0]="1.3.2" [1]="1.3.1" [2]="1.2.3" [3]="1.1.1.5")
$ array=( $(printf "%s\n" "${array[@]}" | sort -V) )
$ typeset -p array
declare -a array=([0]="1.1.1.5" [1]="1.2.3" [2]="1.3.1" [3]="1.3.2")
-V is a natural sort, so sorts them all "correctly" (i.e. in a way that people generally expect for version numbers, e.g. 1.1.1.5 would come before 1.1.1.15 with sort -V but not with sort's default or with sort -n). BTW, GNU ls also has a -v natural sort option so you don't have to zero-pad numbers in file names, and zsh has a (n) glob modifier for natural sorting.
With perl:
$ s='1.3.2 1.3.1 1.2.3 1.1.1.5'
$ echo "$s" | perl -Mversion -lane 'print join " ", sort {
version->parse($a) cmp version->parse($b) } @F'
1.1.1.5 1.2.3 1.3.1 1.3.2
