#!/usr/bin/env etsh
:
: etsh - " Force sh(1), csh(1), and other shells to exit w/ error! " <'' ;;;
:
: "  @(#)$Id: 959078fb7de9e42d0fc2c7665e0842461bd67714 $  "
:
: "  The author of this file, J.A. Neitzel <jan (at) etsh (dot) io>,  "
: "  hereby grants it to the public domain.                           "
:

:
: "  Compare integer1 against integer2 according to the specified operator.  "
: "  Exit with a zero status (true) if the comparison is true, or exit with  "
: "  a non-zero status (false) if the comparison is false.                   "
:
: "  usage: intcmp integer1 {-eq | -ne | -gt | -ge | -lt | -le} integer2  "
:

: " Check for correct usage. "
: >>$0'' <'' ; killer $0 intcmp
: >>$1'' <'' ; : >>$2'' <'' ; : >>$3'' <''

if $# != 3 if { exit } \
	pusage $0 '"integer1 {-eq | -ne | -gt | -ge | -lt | -le} integer2"'

if X$1 != X0 -a ! { \
expr //$1 : '//[1-9][0-9]*'  \> 2 \& //$1 : '//[1-9][0-9]*'  = //$1 : '//.*' \
     \| \
     //$1 : '//-[1-9][0-9]*' \> 3 \& //$1 : '//-[1-9][0-9]*' = //$1 : '//.*' \
} if { exit } perror $0 $1'": Invalid integer"' >/dev/null

if X$3 != X0 -a ! { \
expr //$3 : '//[1-9][0-9]*'  \> 2 \& //$3 : '//[1-9][0-9]*'  = //$3 : '//.*' \
     \| \
     //$3 : '//-[1-9][0-9]*' \> 3 \& //$3 : '//-[1-9][0-9]*' = //$3 : '//.*' \
} if { exit } perror $0 $3'": Invalid integer"' >/dev/null

if X$2 = X-eq if { exit } expr $1   = $3 >/dev/null
if X$2 = X-ne if { exit } expr $1  != $3 >/dev/null
if X$2 = X-gt if { exit } expr $1 \>  $3 >/dev/null
if X$2 = X-ge if { exit } expr $1 \>= $3 >/dev/null
if X$2 = X-lt if { exit } expr $1 \<  $3 >/dev/null
if X$2 = X-le if { exit } expr $1 \<= $3 >/dev/null

perror $0 $2'": Unknown operator"'