Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
declare −a IDX_DIG
# BIG−DIR # DIR_ENT=( $(cat /tmpfs/junk2) )
# BIG−DIR # DigestFile −if /tmpfs/junk2 IDX_DIG
DigestFile DIR_ENT IDX_DIG
# Small (should) be able to parallize IndexList & DigestFile
# Large (should) be able to parallize IndexList & DigestFile & the assignment
echo "The \"name\" (checksum) for the contents of ${PWD} is ${IDX_DIG[0]}"
declare −a FILE_LOC
LocateFile ${PWD} FILE_LOC
ListArray FILE_LOC
exit 0
Stephane Chazelas demonstrates object−oriented programming in a Bash script.
Example A−21. Object−oriented database
#!/bin/bash
# obj−oriented.sh: Object−oriented programming in a shell script.
# Script by Stephane Chazelas.
person.new() # Looks almost like a class declaration in C++.
{
local obj_name=$1 name=$2 firstname=$3 birthdate=$4
}
eval "$obj_name.set_name() {
eval \"$obj_name.get_name() {
echo \$1
}\"
}"
eval "$obj_name.set_firstname() {
eval \"$obj_name.get_firstname() {
echo \$1
}\"
}"
eval "$obj_name.set_birthdate() {
eval \"$obj_name.get_birthdate() {
echo \$1
}\"
eval \"$obj_name.show_birthdate() {
echo \$(date −d \"1/1/1970 0:0:\$1 GMT\")
}\"
eval \"$obj_name.get_age() {
echo \$(( (\$(date +%s) − \$1) / 3600 / 24 / 365 ))
}\"
}"
$obj_name.set_name $name
$obj_name.set_firstname $firstname
$obj_name.set_birthdate $birthdate
echo
Appendix A. Contributed Scripts 405