Bash Trap Stack

Purpose

The traps.sh bash shell script allows you to create a stack of commands to execute for trap.

Commands

• traps_start - registers the exit trap
• traps_push $@ - pushes $@ as one entry to the stack
• traps_pop - pops one entry from the stack and execute
• traps_drop - pops one entry from the stack and do nothing
• traps_isEmpty - returns 0 if empty, returns 1 if not empty
• traps_stop - unregisters the exit trap if there is nothing on the stack
• traps_cancel - unregisters the exit trap and remove all entries from the stack
• traps_exit - unregisters the exit map and pops all entries from the stack
• traps_diag - print the stack on pipe 1

User Variables

• TRAPS_DEBUG=0 - provides more verbose output on pipe 2
• TRAPS_SIGNAL=EXIT - controls the trap signal

Typical Sequence

• traps_start
• traps_push echo "test"
• traps_pop
• traps_stop

Notes

Tested against Bash 5. You can use set -eE along with TRAPS_SIGNAL=ERR before you start the trap stack to get the function and line number that triggered the trap.