use getopt_long() functionality

1 files changed, 76 insertions, 33 deletions

diff --git a/lali.c b/lali.c
index eaad03e..4ffa35b 100644
--- a/lali.c
+++ b/lali.c
@@ -33,6 +33,7 @@
 
 
 #include "liblali.h"
+#include <getopt.h>
 
 #define YEARS                "2025, 2026"
 
@@ -85,38 +86,78 @@ void runREPL(int infd, Object **env, GC_PARAM) {
 }
 
 int main(int argc, char *argv[]) {
-  int options = 0;
-  bool repl = false;
-  bool close = false;
-  bool quiet = false;
-
-  if (argc >= 2) {
-    if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
-      fprintf(stderr, "basic usages:\nnormal:        %s [source]...\nclose stdin:   %s -c [source]...\nrun repl:      %s -r [-q] [source]...\n\nin normal mode, reads from standard input.\nwhen present, load source(s) at startup. can be used as library sources(s).\n", argv[0], argv[0], argv[0]);
-      return EXIT_SUCCESS;
-    } else if (!strcmp(argv[1], "-c")) {
-      options++;
-      close = true;
-    } else if (!strcmp(argv[1], "-r")) {
-      options++;
-      repl = true;
-      if (argc > 2 && !strcmp(argv[2], "-q")) {
-        options++;
-        quiet = true;
-      }
-    } else if (!strcmp(argv[1], "-q")) {
-      options++;
-      quiet = true;
-      if (argc > 2 && !strcmp(argv[2], "-r")) {
-        options++;
-        repl = true;
-      }
-    } else if (argv[1][0] == '-') {
-      fprintf(stderr, "%s: unrecognized option, `%s'\n", argv[0], argv[1]);
-      return EXIT_FAILURE;
-    }
+
+  /// Options processing
+
+  int opt_repl = 0;  // false
+  int opt_close = 0; // false
+  int opt_quiet = 0; // false
+
+  struct option const longopts[] =
+	 {
+		{ "repl",	no_argument,  NULL, 'r' },
+		{ "close",	no_argument,  NULL, 'c' },
+		{ "quiet",	no_argument,  NULL, 'q' },
+		{ "help",	no_argument,  NULL, 'h' },
+		{ 0, 0, 0, 0 }
+	 };
+
+  char const shortopts[] = "crqh";
+
+  while (true) {
+	 int opt = getopt_long(argc, argv, shortopts, longopts, NULL);
+	 if (opt < 0)
+		break;
+
+    switch (opt)
+      {
+      case 0:
+		  /* If getopt returns 0, then it has already processed a
+			  long-named option.  We should do nothing.  */
+		  break;
+
+      case 'h':
+		  /* Show help message. */
+		  fprintf(stdout, "basic usages:\n\
+normal:        %s [file-name]...\n\
+run repl:      %s -r|--repl [-q|--quiet] [file-name]...\n\
+close stdin:   %s -c|--close [file-name]...\n\
+show help:     %s -h|--help\n\
+\n\
+in normal mode, reads from standard input.\n\
+when present, load file-name(s) at startup.  can be used as library file-name(s).\n\
+\n\
+you may use unambiguous abbreviations for the long option names.\n",
+					 argv[0], argv[0], argv[0], argv[0]);
+		  return EXIT_SUCCESS;
+
+		case 'c':
+		  /* Close stdin.  Useful to just use file-name(s), not stdin. */
+		  opt_close = 1; // true
+		  break;
+
+		case 'r':
+		  /* Enter a REPL. */
+		  opt_repl = 1; // true
+		  break;
+
+		case 'q':
+		  /* Supress copyright message. */
+		  opt_quiet = 1; // true
+		  break;
+
+		default:
+		  fprintf (stderr,
+					  "\ttry '%s --help' for a complete list of options.\n",
+					  argv[0]);
+		  return EXIT_FAILURE;
+		}
   }
 
+  int options = opt_close + opt_repl + opt_quiet;
+
+  /// Lisp setting
+
   GC_PARAM = nil;
 
   if (setjmp(exceptionEnv))
@@ -130,6 +171,7 @@ int main(int argc, char *argv[]) {
 
   GC_TRACE(gcEnv, newRootEnv(GC_ROOTS));
 
+  // File sources processing
   int fd = 0;
 
   if (argc > 1) {
@@ -142,18 +184,19 @@ int main(int argc, char *argv[]) {
     }
   }
 
-  if (repl) {
+  // Main processing
+  if (opt_repl) {
     if(!isatty(STDIN_FILENO)) {
       fprintf(stderr, "%s: repl does not accept piping\n", argv[0]);
       return EXIT_FAILURE;
     }
 
-    if (!quiet)
+    if (!opt_quiet)
       fprintf(stdout, "lali Copyright (C) %s Daniel Cerqueira\n\nThis is free software: you are free to change and redistribute it,\nunder certain conditions.\nThis program comes with NO WARRANTY, to the extent permitted by law.\n", YEARS);
 
     runREPL(STDIN_FILENO, gcEnv, GC_ROOTS);
   }
-  else if (!close)
+  else if (!opt_close)
     runFile(STDIN_FILENO, gcEnv, GC_ROOTS);
 
   return EXIT_SUCCESS;