rename a set of files, by changing their prefix - bash

Question

I've got a set of four directories
English.lproj
German.lproj
French.lproj
Italian.lprj
each of this contains a serie of XMLs named
2_symbol.xml
4_symbol.xml
5_symbol.xml
... and so on ...
I need to rename all of these files into another numerical pattern,
because the code that determined those numbers have changed.
so the new numerical pattern would be like
1_symbol.xml
5_symnol.xml
3_symbol.xml
... and so on ...
so there's no algorithm applicable to determine this serie, because of this
reason I thought about storing the two numerical series into an array.
I was thinking to a quick way of doing it with a simple bash script.
I think that I'd need an array to store the old numerical pattern and another
array to store the new numerical pattern, so that I can perform a cycle to make
# move n_symbol.xml newdir/newval_symbol.xml
any suggestion?
thx n cheers.
-k-

Answer 1

you don't need bash for this, any POSIX-compatible shell will do.
repls="1:4 2:1 4:12 5:3"
for pair in $repls; do
old=${pair%:*}
new=${pair#*:}
file=${old}_symbol.xml
mv $file $new${file#$old}
done
edit: you need to take care of overwriting files. the snippet above clobbers 4_symbol.xml, for example.
for pair in $repls; do
...
mv $file $new${file#$old}.tmp
done
for f in *.tmp; do
mv $f ${f%.tmp}
done

Answer 2

The following script will randomly shuffle the symbol names of all xml files across 'lproj' directories.
#!/bin/bash
shuffle() { # Taken from http://mywiki.wooledge.org/BashFAQ/026
local i tmp size max rand
size=${#array[*]}
max=$(( 32768 / size * size ))
for ((i=size-1; i>0; i--)); do
while (( (rand=$RANDOM) >= max )); do :; done
rand=$(( rand % (i+1) ))
tmp=${array[i]} array[i]=${array[rand]} array[rand]=$tmp
done
}
for file in *lproj/*.xml; do # get an array of symbol names
tmp=${file##*/}
array[$((i++))]=${tmp%%_*}
done
shuffle # shuffle the symbol name array
i=0
for file in *lproj/*.xml; do # rename the files with random symbols
echo mv "$file" "${file%%/*}/${array[$((i++))]}_${file##*_}"
done
Note: Remove the echo in front of the mv when you are satisfied with the results and re-run the script to make the changes permanent.
Script Output
$ ./randomize.sh
mv 1.lproj/1_symbol.xml 1.lproj/16_symbol.xml
mv 1.lproj/2_symbol.xml 1.lproj/12_symbol.xml
mv 1.lproj/3_symbol.xml 1.lproj/6_symbol.xml
mv 1.lproj/4_symbol.xml 1.lproj/4_symbol.xml
mv 2.lproj/5_symbol.xml 2.lproj/14_symbol.xml
mv 2.lproj/6_symbol.xml 2.lproj/1_symbol.xml
mv 2.lproj/7_symbol.xml 2.lproj/3_symbol.xml
mv 2.lproj/8_symbol.xml 2.lproj/7_symbol.xml
mv 3.lproj/10_symbol.xml 3.lproj/10_symbol.xml
mv 3.lproj/11_symbol.xml 3.lproj/11_symbol.xml
mv 3.lproj/12_symbol.xml 3.lproj/2_symbol.xml
mv 3.lproj/9_symbol.xml 3.lproj/8_symbol.xml
mv 4.lproj/13_symbol.xml 4.lproj/13_symbol.xml
mv 4.lproj/14_symbol.xml 4.lproj/15_symbol.xml
mv 4.lproj/15_symbol.xml 4.lproj/9_symbol.xml
mv 4.lproj/16_symbol.xml 4.lproj/5_symbol.xml