Shell Expansion

This friday, my friend was developing a shell script in KSH for AIX. In this script, several files with a special naming convention should be selected, but only part of the name should be considered. The format is:

word1-word2-extension-serial1-serial2-name.cmt

Where:

word1: any length

word2: any length 

extension: any length 

serial1: 6 chars 

serial2: 6 chars 

name: any length

So, these name would be ok, for instance:

CONTAB1-PALAVRA2-NMT-123456-123456-gilberto.cmt 

CTB1-PLV2-XYZ-654321-000001-joaozinho.cmt

From those names, everything before the serials should be extracted. That is:

CONTAB1-PALAVRA2-NMT 

CTB1-PLV2-XYZ

At first, the nightmare are the 3 variable length parts and the NAME , which is also variable. But SHELL EXPANSION can beat it. And the best, not only BASH, but it does apply to KSH (I really didn't know that !!!).

So, the solution:

$ var='CONTAB1-PALAVRA2-NMT-123456-123456-gilberto.cmt' 

$ echo ${var%%-??????-??????-*.cmt} 

CONTAB1-PALAVRA2-NMT

The second example:

$ var='CTB1-PLV2-XYZ-654321-000001-joaozinho.cmt' 

$ echo ${var%%-??????-??????-*.cmt} 

CTB1-PLV2-XYZ

Once again, the apparently cryptographic hieroglyphic SHELL did it!!!

:D