Implement --help.

[cdecl99.git] / src / cdecl99.c

diff --git a/src/cdecl99.c b/src/cdecl99.c
index c70834fbb98eeaa015bdff0caa73adda63793fbf..d58433ba15e68774eadfb3549d8f73583102fc5a 100644 (file)
--- a/src/cdecl99.c
+++ b/src/cdecl99.c
@@ -24,9 +24,11 @@
 #include <locale.h>
 #include <getopt.h>
 #include <gettext.h>
+#include <assert.h>
 #include "readline.h"
 #include "cdecl.h"
 
+#define _(x) gettext(x)
 #define N_(x) x
 #define PN_(c, x) x
 
@@ -48,6 +50,30 @@ static const char sopts[] = "qbif:e:VH";
 enum { NOPTS = sizeof (struct option[]){RAW_LOPTS} / sizeof (struct option) };
 static struct option lopts[NOPTS + !!ENABLE_NLS * NOPTS + 1] = { RAW_LOPTS };
 
+static struct helptext {
+       int val;
+       const char *text;
+       const char *argname;
+} helptext[] = {
+       /*
+        * TRANSLATORS: Help messages are indented 20 spaces and thus should
+        * not have lines longer than 60 columns.
+        */
+       { 'q', N_("Suppress the welcome message.\n") },
+       { 'b', N_("Execute commands as normal, but do not print any prompts.\n") },
+       { 'i', N_("Run in interactive mode.  This is the default.\n") },
+       { 'f', N_("Read commands from FILE instead of standard input.\n"),
+              PN_("longopt|file", "FILE") },
+       { 'e', N_("Execute COMMAND as if it were entered at the prompt.\n"
+                 "This can be specified multiple times.\n"),
+              PN_("longopt|execute", "COMMAND") },
+       { 'V', N_("Print a version message and then exit.\n") },
+       { 'H', N_("Print this message.\n") },
+
+       /* TRANSLATORS: ARG is only used for options without help text. */
+       { 0, NULL, PN_("longopt", "ARG") }
+};
+
 static void print_version(void)
 {
        puts(PACKAGE_STRING);
@@ -63,10 +89,114 @@ static void print_usage(FILE *f)
        fprintf(f, "Usage: %s [options]\n", progname);
 }
 
+/*
+ * Print the help description of a particular command-line option, identified
+ * by its short option name.
+ */
+static void print_option(int val)
+{
+       const struct option *tmp[2];
+       const struct helptext *help;
+       const char *argname;
+       char context[32];
+       size_t rc, n = 0;
+       int w;
+
+       /* Find the options and help text corresponding to val. */
+       for (const struct option *o = lopts; o->val; o++) {
+               if (o->val == val) {
+                       assert(n < sizeof tmp / sizeof tmp[0]);
+                       tmp[n++] = o;
+               }
+       }
+
+       for (help = helptext; help->val; help++) {
+               if (help->val == val)
+                       break;
+       }
+
+       /* Prepare translations. */
+       if (!ENABLE_NLS) {
+               argname = help->argname;
+       } else if (n > 0) {
+               rc = snprintf(context, sizeof context, "longopt%c%s",
+                             help->text ? '|' : '\0', tmp[0]->name);
+               assert(rc < sizeof context);
+
+               if (help->argname)
+                       argname = pgettext_expr(context, help->argname);
+       }
+
+       switch (n) {
+       case 0:
+               w = printf(_("  -%c"), val);
+               break;
+       case 1:
+               w = printf(tmp[0]->has_arg ? _("  -%c, --%s=%s")
+                                          : _("  -%c, --%s"),
+                          val, tmp[0]->name, argname);
+               break;
+       case 2:
+               if (tmp[0]->has_arg) {
+                       w = printf(_("  -%c, --%s=%s, --%s=%s"), val,
+                                  tmp[0]->name, argname,
+                                  tmp[1]->name, argname);
+               } else {
+                       w = printf(_("  -%c, --%s, --%s"), val,
+                                  tmp[0]->name, tmp[1]->name);
+               }
+               break;
+       default:
+               assert(0);
+       }
+
+       if (!help->text) {
+               putchar('\n');
+               return;
+       }
+
+       if (w > 18) {
+               putchar('\n');
+               w = 0;
+       }
+
+       for (const char *line = gettext(help->text); *line;) {
+               const char *nl = strchr(line, '\n');
+
+               if (!nl) {
+                       printf("%*s%s\n", 20-w, "", line);
+                       break;
+               }
+
+               printf("%*s%.*s\n", 20-w, "", (int)(nl-line), line);
+               line = nl+1;
+       }
+}
+
 static void print_help(void)
 {
        print_usage(stdout);
-       puts("Detailed help coming soon.");
+
+       puts(_(
+"This is \"cdecl99\": a command-line tool for parsing and constructing\n"
+"complicated C declarations.\n"));
+
+       puts(_("Options:"));
+       for (const char *c = sopts; *c; c++) {
+               if (*c == ':' || *c == '+' || *c == '-')
+                       continue;
+
+               print_option(*c);
+       }
+       putchar('\n');
+
+       puts(_("For more information, see the cdecl99(1) man page.\n"));
+
+       /*
+        * TRANSLATORS: Please add *another line* indicating where users should
+        * report translation bugs.
+        */
+       printf(_("Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 }
 
 /*
@@ -340,9 +470,14 @@ static void init_i18n(void)
        if (!ENABLE_NLS)
                return;
 
-       for (int i = 0; i < NOPTS; i++) {
-               lopts[i+NOPTS] = lopts[i];
-               lopts[i+NOPTS].name = pgettext_expr("longopt", lopts[i].name);
+       for (int i = 0, j = NOPTS; i < NOPTS; i++) {
+               const char *tname = pgettext_expr("longopt", lopts[i].name);
+
+               if (strcmp(tname, lopts[i].name) != 0) {
+                       lopts[j] = lopts[i];
+                       lopts[j].name = tname;
+                       j++;
+               }
        }
 }