Shell Programming and Scripting

Okay, I have posted on here one other time and received very fast help, so I figured I'd post again.

Searched for awhile and couldn't find exactly what I'm looking for.

I am attempting to write a script that will search through a given directory, or search through the current directory, and will convert all the dates in the filenames.

I have many files in the format of :

xxx_xxxxxxxx_DDMMYYYY_sometext.tar

and I want to change each of them to

xxx_xxxxxxxx_YYYYMMDD_sometext.tar

the "sometext" on the end isn't always the same amount of text. but the xxx_xxxxxxxx is always the same length.

I haven't gotten anywhere on this script, been reading tutorials and through the forums and I can't figure out even where to start.

I'd assume it'd be some kind of loop reading in each file until there are no more, and then using a variable to capture DD MM and YYYY, and then doing a mv on the file to YYYYMMDD. Logically I have it, but it's actually writing it that is my problem.

tmp=xxx_xxxxxxxx_DDMMYYYY_sometext.tar

echo $tmp | awk -F"_" '{ print $1"_"$2"_"substr($3,5,4)substr($3,3,2)substr($3,1,2)"_"$4}'

output of this is

xxx_xxxxxxxx_YYYYMMDD_sometext.tar
$

i think this would help u

Code:

#!/bin/ksh
find . -type f -name '*??_????????_[0-9][0-9]*_*.tar' | nawk -v q="'" -F_ -v OFS='_' '
{
  f=$0
  $3=substr($3,5) substr($3,3,2) substr($3,1,2)
  printf("mv %c%s%c %c%s%c\n", q, f, q, q, $0, q)
}'

./testScript.sh
./testScript.sh[7]: nawk: not found


Any way of semi-explaining how that script works and what all that stuff means. I can't quite find a tutorial that goes that in depth.

use 'awk' instead of 'nawk'. (if you have 'gawk' - use that).
Try it first.

Did that, and it ran, but when it runs it prints out the line, but it doesn't actually rename the files. And also, instead of the format being:

YYYYMMDD it's YYYYDDMM

just in case my acronyms are backwards y=year m=month(2 digit month, so january = 01), dd=2 digit day(1st=01)

sorry - my bad:

Code:

#!/bin/ksh
find . -type f -name '*??_????????_[0-9][0-9]*_*.tar' | nawk -v q="'" -F_ -v OFS='_' '
{
  f=$0
  $3=substr($3,5) substr($3,1,2) substr($3,3,2)
  printf("mv %c%s%c %c%s%c\n", q, f, q, q, $0, q)
}'

This script does not rename the files - it just outputs the 'renaming' commands.
Let's make sure the 'mv' commands are correct.

After we're satisfied with that:

Code:

./testScript.sh | sh