Add positional options support

argparse.c

@@ -14,6 +14,7 @@
 
 #define OPT_UNSET 1
 #define OPT_LONG  (1 << 1)
+#define OPT_POSI  (1 << 2) // Positional argument
 
 static const char *
 prefix_skip(const char *str, const char *prefix)
@@ -38,7 +39,9 @@ argparse_error(struct argparse *self, const struct argparse_option *opt,
                const char *reason, int flags)
 {
     (void)self;
-    if (flags & OPT_LONG) {
+    if (flags & OPT_POSI) {
+        fprintf(stderr, "error: option `%s` %s\n", opt->long_name, reason);
+    } else if (flags & OPT_LONG) {
         fprintf(stderr, "error: option `--%s` %s\n", opt->long_name, reason);
     } else {
         fprintf(stderr, "error: option `-%c` %s\n", opt->short_name, reason);
@@ -145,10 +148,29 @@ argparse_options_check(const struct argparse_option *options)
     }
 }
 
+static int
+argparse_pos_opt(struct argparse *self, const struct argparse_option *options)
+{
+    options += self->posidx;
+    for (; options->type != ARGPARSE_OPT_END; options++, self->posidx++) {
+        if (!(options->flags & OPT_POSITIONAL)) {
+            continue;
+        }
+
+        self->posidx++;
+        return argparse_getvalue(self, options, OPT_POSI);
+    }
+    return -2;
+}
+
 static int
 argparse_short_opt(struct argparse *self, const struct argparse_option *options)
 {
     for (; options->type != ARGPARSE_OPT_END; options++) {
+        if (options->flags & OPT_POSITIONAL) {
+            continue;
+        }
+
         if (options->short_name == *self->optvalue) {
             self->optvalue = self->optvalue[1] ? self->optvalue + 1 : NULL;
             return argparse_getvalue(self, options, 0);
@@ -163,6 +185,10 @@ argparse_long_opt(struct argparse *self, const struct argparse_option *options)
     for (; options->type != ARGPARSE_OPT_END; options++) {
         const char *rest;
         int opt_flags = 0;
+        if (options->flags & OPT_POSITIONAL) {
+            continue;
+        }
+
         if (!options->long_name)
             continue;
 
@@ -229,6 +255,14 @@ argparse_parse(struct argparse *self, int argc, const char **argv)
     for (; self->argc; self->argc--, self->argv++) {
         const char *arg = self->argv[0];
         if (arg[0] != '-' || !arg[1]) {
+            self->optvalue = arg;
+            switch (argparse_pos_opt(self, self->options)) {
+            case 0:
+                continue;
+            case -1:
+                break;
+            }
+
             if (self->flags & ARGPARSE_STOP_AT_NON_OPTION) {
                 goto end;
             }
@@ -318,7 +352,10 @@ argparse_usage(struct argparse *self)
             len += 2;           // separator ", "
         }
         if ((options)->long_name) {
-            len += strlen((options)->long_name) + 2;
+            len += strlen((options)->long_name);
+            if (!(options->flags & OPT_POSITIONAL)) {
+                len += 2;
+            }
         }
         if (options->type == ARGPARSE_OPT_INTEGER) {
             len += strlen("=<int>");
@@ -353,7 +390,11 @@ argparse_usage(struct argparse *self)
             pos += fprintf(stdout, ", ");
         }
         if (options->long_name) {
-            pos += fprintf(stdout, "--%s", options->long_name);
+            if (options->flags & OPT_POSITIONAL) {
+                pos += fprintf(stdout, "%s", options->long_name);
+            } else {
+                pos += fprintf(stdout, "--%s", options->long_name);
+            }
         }
         if (options->type == ARGPARSE_OPT_INTEGER) {
             pos += fprintf(stdout, "=<int>");
@@ -391,4 +432,3 @@ argparse_help_cb(struct argparse *self, const struct argparse_option *option)
     argparse_help_cb_no_exit(self, option);
     exit(EXIT_SUCCESS);
 }
-

argparse.h

@@ -41,6 +41,7 @@ enum argparse_option_type {
 
 enum argparse_option_flags {
     OPT_NONEG = 1,              /* disable negation */
+    OPT_POSITIONAL = 2,         /* option is positional */
 };
 
 /**
@@ -98,6 +99,7 @@ struct argparse {
     const char **argv;
     const char **out;
     int cpidx;
+    int posidx;                 // index of next option to check if positional
     const char *optvalue;       // current option value
 };
 

tests/basic.c

@@ -4,7 +4,7 @@
 #include "argparse.h"
 
 static const char *const usages[] = {
-    "basic [options] [[--] args]",
+    "basic [options] posi poss [[--] args]",
     "basic [options]",
     NULL,
 };
@@ -21,6 +21,8 @@ main(int argc, const char **argv)
     int int_num = 0;
     float flt_num = 0.f;
     const char *path = NULL;
+    int posi = 0;
+    const char *poss = NULL;
     int perms = 0;
     struct argparse_option options[] = {
         OPT_HELP(),
@@ -34,6 +36,9 @@ main(int argc, const char **argv)
         OPT_BIT(0, "read", &perms, "read perm", NULL, PERM_READ, OPT_NONEG),
         OPT_BIT(0, "write", &perms, "write perm", NULL, PERM_WRITE, 0),
         OPT_BIT(0, "exec", &perms, "exec perm", NULL, PERM_EXEC, 0),
+        OPT_GROUP("Positional options"),
+        OPT_INTEGER(0, "posi", &posi, "positional integer", NULL, 0, OPT_POSITIONAL),
+        OPT_STRING(0, "poss", &poss, "positional string", NULL, 0, OPT_POSITIONAL),
         OPT_END(),
     };
 
@@ -51,6 +56,10 @@ main(int argc, const char **argv)
         printf("int_num: %d\n", int_num);
     if (flt_num != 0)
         printf("flt_num: %g\n", flt_num);
+    if (posi != 0)
+        printf("posi: %d\n", posi);
+    if (poss != NULL)
+        printf("poss: %s\n", poss);
     if (argc != 0) {
         printf("argc: %d\n", argc);
         int i;

tests/basic.sh

@@ -3,10 +3,12 @@
 . $(dirname ${BASH_SOURCE[0]})/tap-functions
 plan_no_plan
 
-is "$(./basic -f --path=/path/to/file a 2>&1)" 'force: 1
+is "$(./basic -f 42 --path=/path/to/file a b 2>&1)" 'force: 1
 path: /path/to/file
+posi: 42
+poss: a
 argc: 1
-argv[0]: a'
+argv[0]: b'
 
 is "$(./basic -f -f --force --no-force 2>&1)" 'force: 2'
 
@@ -18,6 +20,8 @@ is "$(./basic -i2 2>&1)" 'int_num: 2'
 
 is "$(./basic -ia 2>&1)" 'error: option `-i` expects an integer value'
 
+is "$(./basic a 2>&1)" 'error: option `posi` expects an integer value'
+
 is "$(./basic -i 0xFFFFFFFFFFFFFFFFF 2>&1)" \
    'error: option `-i` numerical result out of range'
 
@@ -41,7 +45,7 @@ test: 1'
 
 is "$(./basic --read --write 2>&1)" 'perms: 3'
 
-help_usage='Usage: basic [options] [[--] args]
+help_usage='Usage: basic [options] posi poss [[--] args]
    or: basic [options]
 
 A brief description of what the program does and how it works.
@@ -60,6 +64,10 @@ Bits options
     --write               write perm
     --exec                exec perm
 
+Positional options
+    posi=<int>            positional integer
+    poss=<str>            positional string
+
 Additional description of the program after the description of the arguments.'
 
 is "$(./basic -h)" "$help_usage"