# The following program shows how to use SRgetopt to process
# a command that takes the options 'a', 'b', 'f', and 'w' where
# 'f' is followed by a file name and 'w' is followed by an integer.
# Any other option causes getopt to print an error message and
# return a '?', and the program terminates with a stop.
# (Based on the example contained in SRgetopt.sr distributed with SR.)

resource test_getopt()
   import SRgetopt
   var ch: char
   # process options in command line arguments
   var aflg : int := 0                       # set
   var bflg : bool := false                  # option
   var filename: string[optMAXLEN] := "out"  # default
   var width : int := 80                     # values
   do (ch := getopt("abf:w:")) != optEOF ->
      if ch = 'a' -> aflg++
      [] ch = 'b' -> bflg := true
      [] ch = 'f' -> filename := optarg
      [] ch = 'w' -> width := int(optarg)
      [] else -> stop(1)                   # catch undefined options here,
      fi                                   # getopt returns '?'
   od
   write("-a", aflg)
   write("-b", bflg)
   write("-f", filename)
   write("-w", width)
   # process non-option command line arguments
   fa k := optind to numargs() ->   # getopt sets optind
      var carg: string[40]
      getarg(k, carg)
      write("normal argument", k, "is", carg)
   af
end test_getopt

/* ............... Example compile and run(s)

% sr -o test_getopt test_getopt.sr
% ./test_getopt
-a 0
-b false
-f out
-w 80
% ./test_getopt a1 a2 a3
-a 0
-b false
-f out
-w 80
normal argument 1 is a1
normal argument 2 is a2
normal argument 3 is a3
% ./test_getopt -a -b -f abc -w123 a1 a2 a3
-a 1
-b true
-f abc
-w 123
normal argument 6 is a1
normal argument 7 is a2
normal argument 8 is a3
% ./test_getopt -x a1 a2 a3
./test_getopt: illegal option -- x
% ./test_getopt -a -fabc -x -w 123 -fdef a1 a2 a3
./test_getopt: illegal option -- x
% ./test_getopt -a -fabc -a -w 123 -f def a1 a2 a3
-a 2
-b false
-f def
-w 123
normal argument 8 is a1
normal argument 9 is a2
normal argument 10 is a3
% ./test_getopt -a -f -w123 -a a1 a2 a3
-a 2
-b false
-f -w123
-w 80
normal argument 5 is a1
normal argument 6 is a2
normal argument 7 is a3
% ./test_getopt -a -f -w 123 -a a1 a2 a3
-a 1
-b false
-f -w
-w 80
normal argument 4 is 123
normal argument 5 is -a
normal argument 6 is a1
normal argument 7 is a2
normal argument 8 is a3
% ./test_getopt -b -w123 -f a1 a2 a3
-a 0
-b true
-f a1
-w 123
normal argument 5 is a2
normal argument 6 is a3
% ./test_getopt -a -f
./test_getopt: option requires an argument -- f
% ./test_getopt -a -ab -a -b a1 a2 a3
-a 3
-b true
-f out
-w 80
normal argument 5 is a1
normal argument 6 is a2
normal argument 7 is a3
% ./test_getopt -a -w abc -f 123 a1 a2 a3
RTS abort: file test_getopt.sr, line 20:
   illegal conversion: int("abc")
% ./test_getopt -a 123 -f abc a1 a2 a3
-a 1
-b false
-f out
-w 80
normal argument 2 is 123
normal argument 3 is -f
normal argument 4 is abc
normal argument 5 is a1
normal argument 6 is a2
normal argument 7 is a3
% ./test_getopt -a123 -f def a1 a2 a3
./test_getopt: illegal option -- 1
% ./test_getopt -a -babc -f def -w 123 a1 a2 a3
./test_getopt: illegal option -- c
                                              */