wflinfo: make errors parsable

Previously, if there was an error, then wflinfo would
print various not easily parsable messages to stderr.

Now, all output will be printed to stdout, and will
follow a similar format to the normal wflinfo output.

Errors from the waffle library will show up like:
Waffle error: 0x%x Some string

Additionally, these may be printed:
Wflinfo error: Misc error w/o a waffle error code
Wflinfo usage error: usage error message (see wflinfo --help)

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

1 files changed, 19 insertions, 15 deletions

diff --git a/src/utils/wflinfo.c b/src/utils/wflinfo.c
index 39fc44a..dd70a4e 100644
--- a/src/utils/wflinfo.c
+++ b/src/utils/wflinfo.c
@@ -124,16 +124,16 @@ static const struct option get_opts[] = {
 ///
 
 static void __attribute__((noreturn))
-error_printf(const char *fmt, ...)
+error_printf(const char *module, const char *fmt, ...)
 {
     va_list ap;
 
     fflush(stdout);
 
     va_start(ap, fmt);
-    fprintf(stderr, "wflinfo: error: ");
-    vfprintf(stderr, fmt, ap);
-    fprintf(stderr, "\n");
+    printf("%s error: ", module);
+    vprintf(fmt, ap);
+    printf("\n");
     va_end(ap);
 
     exit(EXIT_FAILURE);
@@ -150,19 +150,18 @@ static void __attribute__((noreturn))
 usage_error_printf(const char *fmt, ...)
 {
     fflush(stdout);
-    fprintf(stderr, "wflinfo: usage error");
+    printf("Wflinfo usage error: ");
 
     if (fmt) {
         va_list ap;
         va_start(ap, fmt);
-        fprintf(stderr, ": ");
-        vfprintf(stderr, fmt, ap);
+        vprintf(fmt, ap);
         va_end(ap);
+        printf(" ");
     }
 
-    fprintf(stderr, "\n");
-    fprintf(stderr, "\n");
-    write_usage_and_exit(stderr, EXIT_FAILURE);
+    printf("(see wflinfo --help)\n");
+    exit(EXIT_FAILURE);
 }
 
 static void
@@ -172,15 +171,15 @@ error_waffle(void)
     const char *code = waffle_error_to_string(info->code);
 
     if (info->message_length > 0)
-        error_printf("%s: %s", code, info->message);
+        error_printf("Waffle", "0x%x %s: %s", info->code, code, info->message);
     else
-        error_printf("%s", code);
+        error_printf("Waffle", "0x%x %s", info->code, code);
 }
 
 static void
 error_get_gl_symbol(const char *name)
 {
-    error_printf("failed to get function pointer for %s", name);
+    error_printf("Wflinfo", "failed to get function pointer for %s", name);
 }
 
 /// @}
@@ -316,6 +315,9 @@ parse_args(int argc, char *argv[], struct options *opts)
     opts->context_profile = -1;
     opts->context_version = -1;
 
+    // prevent getopt_long from printing an error message
+    opterr = 0;
+
     while (loop_get_opt) {
         int opt = getopt_long(argc, argv, "a:p:vV:", get_opts, NULL);
         switch (opt) {
@@ -412,8 +414,10 @@ parse_args(int argc, char *argv[], struct options *opts)
 error_unrecognized_arg:
     if (optarg)
         usage_error_printf("unrecognized option '%s'", optarg);
+    else if (optopt)
+        usage_error_printf("unrecognized option '-%c'", optopt);
     else
-        usage_error_printf("parameter error");
+        usage_error_printf("unrecognized option");
 }
 
 /// @}
@@ -653,7 +657,7 @@ main(int argc, char **argv)
         error_waffle();
 
     if (!waffle_display_supports_context_api(dpy, opts.context_api)) {
-        error_printf("Display does not support %s",
+        error_printf("Wflinfo", "Display does not support %s",
                      waffle_enum_to_string(opts.context_api));
     }