From c539a19833ba93df88f67a878b1d68fc468fb88d Mon Sep 17 00:00:00 2001
From: dave <dave@davepedu.com>
Date: Sun, 22 Jul 2018 15:14:07 -0700
Subject: [PATCH] add 'arg required' flag to argparse

---
 src/main.c            |  4 ++--
 src/vendor/argparse.c | 33 ++++++++++++++++++++++++---------
 src/vendor/argparse.h |  9 +++++----
 3 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/main.c b/src/main.c
index 8534f7a..9ee0158 100644
--- a/src/main.c
+++ b/src/main.c
@@ -13,8 +13,8 @@ int main(int argc, const char** argv) {
 
     struct argparse_option options[] = {
         OPT_HELP(),
-        OPT_INTEGER('p', "port", &port, "server port"),
-        OPT_STRING ('u', "url",  &url,  "elasticsearch url"),
+        OPT_INTEGER('p', "port", &port, "server port",       .flags = OPT_REQUIRED),
+        OPT_STRING ('u', "url",  &url,  "elasticsearch url", .flags = OPT_REQUIRED),
         OPT_END()
     };
 
diff --git a/src/vendor/argparse.c b/src/vendor/argparse.c
index 92ec391..1f8da93 100644
--- a/src/vendor/argparse.c
+++ b/src/vendor/argparse.c
@@ -34,7 +34,7 @@ prefix_cmp(const char *str, const char *prefix)
 }
 
 static void
-argparse_error(struct argparse *self, const struct argparse_option *opt,
+argparse_error(struct argparse *self, struct argparse_option *opt,
                const char *reason, int flags)
 {
     (void)self;
@@ -47,7 +47,7 @@ argparse_error(struct argparse *self, const struct argparse_option *opt,
 }
 
 static int
-argparse_getvalue(struct argparse *self, const struct argparse_option *opt,
+argparse_getvalue(struct argparse *self, struct argparse_option *opt,
                   int flags)
 {
     const char *s = NULL;
@@ -118,6 +118,8 @@ argparse_getvalue(struct argparse *self, const struct argparse_option *opt,
         assert(0);
     }
 
+    opt->flags &= ~OPT_REQUIRED;
+
 skipped:
     if (opt->callback) {
         return opt->callback(self, opt);
@@ -127,7 +129,7 @@ skipped:
 }
 
 static void
-argparse_options_check(const struct argparse_option *options)
+argparse_options_check(struct argparse_option *options)
 {
     for (; options->type != ARGPARSE_OPT_END; options++) {
         switch (options->type) {
@@ -147,7 +149,7 @@ argparse_options_check(const struct argparse_option *options)
 }
 
 static int
-argparse_short_opt(struct argparse *self, const struct argparse_option *options)
+argparse_short_opt(struct argparse *self, struct argparse_option *options)
 {
     for (; options->type != ARGPARSE_OPT_END; options++) {
         if (options->short_name == *self->optvalue) {
@@ -159,7 +161,7 @@ argparse_short_opt(struct argparse *self, const struct argparse_option *options)
 }
 
 static int
-argparse_long_opt(struct argparse *self, const struct argparse_option *options)
+argparse_long_opt(struct argparse *self, struct argparse_option *options)
 {
     for (; options->type != ARGPARSE_OPT_END; options++) {
         const char *rest;
@@ -218,6 +220,17 @@ argparse_describe(struct argparse *self, const char *description,
     self->epilog      = epilog;
 }
 
+void
+argparse_check_required(struct argparse* self) {
+    struct argparse_option *opt;
+    opt = self->options;
+    for (; opt->type != ARGPARSE_OPT_END; opt++) {
+        if(opt->flags & OPT_REQUIRED) {
+            argparse_error(self, opt, "is required", OPT_LONG);
+        }
+    }
+}
+
 int
 argparse_parse(struct argparse *self, int argc, const char **argv)
 {
@@ -282,6 +295,8 @@ end:
             self->argc * sizeof(*self->out));
     self->out[self->cpidx + self->argc] = NULL;
 
+    argparse_check_required(self);
+
     return self->cpidx + self->argc;
 }
 
@@ -302,13 +317,13 @@ argparse_usage(struct argparse *self)
 
     fputc('\n', stdout);
 
-    const struct argparse_option *options;
+    struct argparse_option *options;
 
     // figure out best width
     size_t usage_opts_width = 0;
-    size_t len;
     options = self->options;
     for (; options->type != ARGPARSE_OPT_END; options++) {
+        size_t len;
         len = 0;
         if ((options)->short_name) {
             len += 2;
@@ -321,7 +336,7 @@ argparse_usage(struct argparse *self)
         }
         if (options->type == ARGPARSE_OPT_INTEGER) {
             len += strlen("=<int>");
-          }
+		  }
         if (options->type == ARGPARSE_OPT_FLOAT) {
             len += strlen("=<flt>");
         } else if (options->type == ARGPARSE_OPT_STRING) {
@@ -377,7 +392,7 @@ argparse_usage(struct argparse *self)
 }
 
 int
-argparse_help_cb(struct argparse *self, const struct argparse_option *option)
+argparse_help_cb(struct argparse *self, struct argparse_option *option)
 {
     (void)option;
     argparse_usage(self);
diff --git a/src/vendor/argparse.h b/src/vendor/argparse.h
index 7fff31d..dfad4b0 100644
--- a/src/vendor/argparse.h
+++ b/src/vendor/argparse.h
@@ -19,7 +19,7 @@ struct argparse;
 struct argparse_option;
 
 typedef int argparse_callback (struct argparse *self,
-                               const struct argparse_option *option);
+                               struct argparse_option *option);
 
 enum argparse_flag {
     ARGPARSE_STOP_AT_NON_OPTION = 1,
@@ -39,7 +39,8 @@ enum argparse_option_type {
 };
 
 enum argparse_option_flags {
-    OPT_NONEG = 1,              /* disable negation */
+    OPT_NONEG = 0x01,              /* disable negation */
+    OPT_REQUIRED = 0x02,           /* opt must be passed */
 };
 
 /**
@@ -87,7 +88,7 @@ struct argparse_option {
  */
 struct argparse {
     // user supplied
-    const struct argparse_option *options;
+    struct argparse_option *options;
     const char *const *usages;
     int flags;
     const char *description;    // a description after usage
@@ -102,7 +103,7 @@ struct argparse {
 
 // built-in callbacks
 int argparse_help_cb(struct argparse *self,
-                     const struct argparse_option *option);
+                     struct argparse_option *option);
 
 // built-in option macros
 #define OPT_END()        { ARGPARSE_OPT_END, 0, NULL, NULL, 0, NULL, 0, 0 }