linux - shell script to rename files in folder keeping order -

in folder have several files like

name_1.txt name_2.txt name_12.txt name_13.txt 

and rename them in

name_1.txt -> name_1.txt name_2.txt -> name_2.txt name_12.txt -> name_3.txt name_13.txt -> name_4.txt 

the following code partially job, doesn't keep order

#!/bin/sh num=1 file in *.txt;        mv "$file" "$(printf "%u" $num).txt"        let num=$num+1 done 

indeed output is

name_1.txt -> 1.txt name_2.txt -> 4.txt name_12.txt -> 2.txt name_13.txt -> 3.txt 

how fix name , order? thanks!

the *.txt expands name_12.txt name_13.txt name_1.txt name_2.txt because makes sense computer. need sort start off in our human way. ls command can nicely natural sort ls -v *.txt.

this means code need this...

#!/bin/sh num=1 file in $(ls -v *.txt);    mv "$file" "$(printf "%u" $num).txt"    let num=$num+1 done