The ifte program
ifte performs a conditional alternative.
Interface
In an execlineb script:
ifte [ -X ] [ -n ] { progthen... } { progelse... } progif...
- ifte reads progthen... and progelse... in two consecutive blocks.
- ifte runs progif... as a child process and waits for it to complete.
- If progif... crashes (i.e. is killed by a signal), ifte prints an error message, then exits 128 plus the number of the signal that killed progif.
- If progif... exits zero, ifte execs into progthen..., else it execs into progelse....
Options
- -X : do not exit if progif crashes; instead, proceed as if the test had returned false.
- -n : negate the test. progthen... will be run iff progif... exits nonzero.
Notes
ifte is a simpler version of ifthenelse. It performs only conditional execution, not instruction sequence.
"ifthenelse { progif } { progthen } { progelse } remainder" is the equivalent of "foreground { ifte { progthen } { progelse } progif } remainder".