CE Implement positional arguments

ce/ce.c

@@ -8,6 +8,7 @@
 #include <in_gb.h>
 #include <in_input.h>
 #include <malloc.h>
+#include <minmax.h>
 #include <mprintf.h>
 #include <path.h>
 #include <printf.h>
@@ -77,8 +78,23 @@ static bool split_lines_cb (void* ctx, const char* start, size_t len) {
   return true;
 }
 
+static bool split_args_cb (void* ctx, const char* start, size_t len) {
+  (void)ctx;
+
+  if (posvar_count >= POSVAR_MAX)
+    return false;
+
+  struct posvar* posvar = &posvars[posvar_count++];
+  memset (posvar, 0, sizeof (*posvar));
+
+  memcpy (posvar->buf, start, min (len, sizeof (posvar->buf) - 1));
+
+  return true;
+}
+
 void app_main (void) {
   char scriptpathbuf[PATH_MAX];
+  char posvarsbuf[2048];
   char line[1024];
 
   memset (scriptpathbuf, 0, sizeof (scriptpathbuf));
@@ -87,6 +103,10 @@ void app_main (void) {
   if (has_script == ST_OK) {
     interactive_mode = false;
 
+    if (env_get (process_get_pgid (), "args", (void*)posvarsbuf, sizeof (posvarsbuf)) == ST_OK) {
+      strtokenize (posvarsbuf, ' ', NULL, &split_args_cb);
+    }
+
     char volume[VOLUME_MAX];
     const char* path;
     int ret;

ce/interp.c

@@ -30,6 +30,9 @@ static bool run = true;
 
 bool interactive_mode;
 
+struct posvar posvars[POSVAR_MAX];
+int posvar_count = 0;
+
 bool interp_is_running (void) { return run; }
 
 void interp_shutdown (void) { run = false; }

ce/interp.h

@@ -3,8 +3,15 @@
 
 #include "context.h"
 #include "parser.h"
+#include <list.h>
 #include <stdbool.h>
 
+#define POSVAR_MAX 64
+
+struct posvar {
+  char buf[0x80];
+};
+
 void execute (struct ast_node* root, struct context* context, bool run_bg);
 
 bool interp_is_running (void);
@@ -13,4 +20,7 @@ void interp_shutdown (void);
 
 extern bool interactive_mode;
 
+extern struct posvar posvars[POSVAR_MAX];
+extern int posvar_count;
+
 #endif // _INTERP_H

ce/parser.c

@@ -5,6 +5,7 @@
 #include <arena.h>
 #include <list.h>
 #include <mprintf.h>
+#include <strconv.h>
 #include <string.h>
 
 static struct parse_rule parse_rules[] = {
@@ -162,6 +163,29 @@ void tokenize (struct list_node_link** tokens, const char* text) {
     if (*p == '#')
       return;
 
+    if (*p == '$') {
+      p++;
+      struct token* token = arena_malloc (&arena, sizeof (*token));
+      memset (token, 0, sizeof (*token));
+      size_t i = 0;
+      char numbuf[TOKEN_MAX];
+
+      while (*p && isdigit (*p)) {
+        numbuf[i++] = *p;
+        p++;
+      }
+
+      numbuf[i] = '\0';
+      uint32_t idx = str_to_uint32 (numbuf) % posvar_count;
+      struct posvar* posvar = &posvars[idx];
+
+      memcpy (token->buffer, posvar->buf, sizeof (posvar->buf));
+      token->class = TOKEN_CLASS_WORD;
+      list_append (*tokens, &token->tokens_link);
+
+      continue;
+    }
+
     if (*p == '"') {
       p++;
       struct token* token = arena_malloc (&arena, sizeof (*token));
@@ -218,7 +242,15 @@ void tokenize (struct list_node_link** tokens, const char* text) {
       memset (token, 0, sizeof (*token));
       size_t i = 0;
 
-      while (*p && !isspace (*p) && *p != '(' && *p != ')' && *p != ';' && *p != '>' && *p != '"') {
+      while (*p &&
+             !isspace (*p) &&
+             *p != '(' &&
+             *p != ')' &&
+             *p != ';' &&
+             *p != '>' &&
+             *p != '"' &&
+             *p != '#' &&
+             *p != '$') {
         if (i < TOKEN_MAX - 1)
           token->buffer[i++] = *p;
         p++;