string templating possibly working

Makefile

 appname = housecat
 
 build:
-	gcc -O3 -o $(appname) src/*.c -std=c99 -D_XOPEN_SOURCE=700
+	gcc -o $(appname) -O3 src/*.c -std=c99 -D_XOPEN_SOURCE=700
 
 debug:
-	gcc -o $(appname) src/*.c -std=c99 -DDEBUG=1 -D_XOPEN_SOURCE=700
+	gcc -o $(appname) -Wall -Wextra src/*.c -std=c99 -DDEBUG=1 -D_XOPEN_SOURCE=700
 
 install:
 	mv $(appname) /usr/bin/$(appname)

src/cms_build.c

 #include <string.h>
 
 #include "cms_build.h"
+#include "cms_template.h"
 #include "cms_err.h"
 #include "cms_files.h"
 #include "cms_util.h"

src/cms_err.c

 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
-#ifdef DEBUG
-	#include <error.h>
-#endif
 
 #include "cms_err.h"
 

src/cms_template.c

 	if (args->argnum > args->allocd)
 	{
 		args->allocd *= 2;
-		args->arguments = realloc(args->arguments, sizeof(cms_template_arg) * args->allocd);
+		args->arguments = realloc(
+			args->arguments,
+			sizeof(cms_template_arg) * args->allocd
+		);
 		if (!args->arguments)
 			return cms_err_create(CMS_ERR_ALLOC, 0);
 	}
 	return cms_err_create(CMS_ERR_NONE, NULL);
 }
 
-static cms_err* str_insert(char* str1, char* str2, size_t start, size_t end, size_t len)
+static char* str_insert(
+		char* str1,
+		char* str2,
+		size_t start,
+		size_t end,
+		size_t len)
 {
 	size_t len2 = strlen(str2);
 
-	return cms_err_create(CMS_ERR_NONE, NULL);
+	str1 = realloc(str1, len + len2 - (end - start));
+	if (str1 == NULL)
+		return NULL;
+
+	memmove(str1 + end, str1 + start, len - start);
+	memcpy(str1 + start, str2, len2);
+
+	return str1;
 }
 
-static cms_err* templatify_arg(char* str, cms_template_arg arg, size_t len)
+static char* templatify_arg(char* str, cms_template_arg arg, size_t len)
 {
-	#define OFFSET i - match_begin
+	#define OFFSET i - match_start
 
-	size_t match_begin = -1;
+	size_t match_start = 0;
 	size_t i = 0;
+	int in_match = 0;
 
 	char c;
 	while ((c = str[i]) != 0)
 	{
-		if (match_begin == -1 && arg.key[0] == c)
+		if (!in_match && arg.key[0] == c)
 		{
-			match_begin = i;
+			match_start = i;
+			in_match = 1;
 		}
 
-		if (match_begin != -1 && arg.key[OFFSET] == 0)
+		if (in_match && arg.key[OFFSET] != 0)
 		{
+			if (arg.key[OFFSET] != c)
+				in_match = 0;
+		}
+		else if (in_match)
+		{
+			str = str_insert(str, arg.val, match_start, i, len);
+			if (str == NULL)
+				return NULL;
+
+			in_match = 0;
 		}
 
 		i += 1;
 
 	#undef OFFSET
 
-	return cms_err_create(CMS_ERR_NONE, NULL);
+	return str;
 }
 
-cms_err* cms_templateify(char* str, cms_template_args* args)
+char* cms_templateify(char* str, cms_template_args* args)
 {
 	size_t len = strlen(str);
 
 	size_t i;
 	for (i = 0; i < args->argnum; ++i)
 	{
-		cms_err* err = templatify_arg(str, args->arguments[i], len);
-		if (err)
-			return err;
+		str = templatify_arg(str, args->arguments[i], len);
+		if (str == NULL)
+			return NULL;
 	}
 
-	return cms_err_create(CMS_ERR_NONE, NULL);
+	return str;
 }

src/cms_template.h

 
 cms_err* cms_template_args_append(cms_template_args* args, char* key, char* val);
 
-cms_err* cms_templateify(char* name, cms_template_args* args);
+char* cms_templateify(char* str, cms_template_args* args);
 
 #endif