diff options
| -rw-r--r-- | xgamma.c | 40 |
1 files changed, 25 insertions, 15 deletions
@@ -44,8 +44,11 @@ static int EventBase, ErrorBase; #define GAMMA_MAX 10.0 static void _X_NORETURN -Syntax(void) +Syntax(const char *errmsg) { + if (errmsg != NULL) + fprintf (stderr, "%s: %s\n\n", ProgramName, errmsg); + fprintf (stderr, "usage: %s [-options]\n\n%s", ProgramName, "where the available options are:\n" " -display host:dpy or -d\n" @@ -104,20 +107,20 @@ main(int argc, char *argv[]) if (arg[0] == '-') { if (isabbreviation ("-display", arg, 1)) { - if (++i >= argc) Syntax (); + if (++i >= argc) Syntax ("-display requires an argument"); displayname = argv[i]; continue; } else if (isabbreviation ("-quiet", arg, 1)) { quiet = True; continue; } else if (isabbreviation ("-screen", arg, 1)) { - if (++i >= argc) Syntax (); + if (++i >= argc) Syntax ("-screen requires an argument"); screen = atoi(argv[i]); continue; } else if (isabbreviation ("-gamma", arg, 2)) { - if (++i >= argc) Syntax (); + if (++i >= argc) Syntax ("-gamma requires an argument"); if ((rgam >= 0.) || (ggam >= 0.) || (bgam >= 0.)) - Syntax (); + Syntax ("-gamma cannot be used with -rgamma, -ggamma, or -bgamma"); gam = (float)atof(argv[i]); if ((gam < GAMMA_MIN) || (gam > GAMMA_MAX)) { fprintf(stderr, @@ -127,8 +130,8 @@ main(int argc, char *argv[]) } continue; } else if (isabbreviation ("-rgamma", arg, 2)) { - if (++i >= argc) Syntax (); - if (gam >= 0.) Syntax (); + if (++i >= argc) Syntax ("-rgamma requires an argument"); + if (gam >= 0.) Syntax ("cannot set both -gamma and -rgamma"); rgam = (float)atof(argv[i]); if ((rgam < GAMMA_MIN) || (rgam > GAMMA_MAX)) { fprintf(stderr, @@ -138,8 +141,8 @@ main(int argc, char *argv[]) } continue; } else if (isabbreviation ("-ggamma", arg, 2)) { - if (++i >= argc) Syntax (); - if (gam >= 0.) Syntax (); + if (++i >= argc) Syntax ("-ggamma requires an argument"); + if (gam >= 0.) Syntax ("cannot set both -gamma and -ggamma"); ggam = (float)atof(argv[i]); if ((ggam < GAMMA_MIN) || (ggam > GAMMA_MAX)) { fprintf(stderr, @@ -149,8 +152,8 @@ main(int argc, char *argv[]) } continue; } else if (isabbreviation ("-bgamma", arg, 2)) { - if (++i >= argc) Syntax (); - if (gam >= 0.) Syntax (); + if (++i >= argc) Syntax ("-bgamma requires an argument"); + if (gam >= 0.) Syntax ("cannot set both -gamma and -bgamma"); bgam = (float)atof(argv[i]); if ((bgam < GAMMA_MIN) || (bgam > GAMMA_MAX)) { fprintf(stderr, @@ -159,10 +162,17 @@ main(int argc, char *argv[]) exit(1); } continue; - } else - Syntax (); - } else - Syntax (); + } else { + if (!isabbreviation ("-help", arg, 1)) + fprintf (stderr, "%s: unrecognized argument %s\n\n", + ProgramName, arg); + Syntax (NULL); + } + } else { + fprintf (stderr, "%s: unrecognized argument %s\n\n", + ProgramName, arg); + Syntax (NULL); + } } if ((dpy = XOpenDisplay(displayname)) == NULL) { |