New expand_tilde() utility function

Add new `expand_tilde' utility function which substitutes
leading `~/' for the current user's home directory in path
names; NB: returns a new string the caller must free when
it's not needed anymore.

devcmd.c

@@ -333,7 +333,15 @@ struct hexout_data {
 
 static int hexout_start(struct hexout_data *hexout, const char *filename)
 {
-	hexout->file = fopen(filename, "w");
+	char * path = NULL;
+
+	path = expand_tilde(filename);
+	if (!path)
+		return -1;
+
+	hexout->file = fopen(path, "w");
+	free(path);
+
 	if (!hexout->file) {
 		pr_error("hexout: couldn't open output file");
 		return -1;
@@ -492,11 +500,17 @@ static int do_cmd_prog(char **arg, int prog_flags)
 {
 	FILE *in;
 	struct prog_data prog;
+	char * path;
 
 	if (prompt_abort(MODIFY_SYMS))
 		return 0;
 
-	in = fopen(*arg, "rb");
+	path = expand_tilde(*arg);
+	if (!path)
+		return -1;
+
+	in = fopen(path, "rb");
+	free(path);
 	if (!in) {
 		printc_err("prog: %s: %s\n", *arg, last_error());
 		return -1;

reader.c

@@ -227,10 +227,15 @@ int process_command(char *cmd)
 int process_file(const char *filename, int show)
 {
 	FILE *in;
-	char buf[1024];
+	char buf[1024], *path;
 	int line_no = 0;
 
+	path = expand_tilde(filename);
+	if (!path)
+		return -1;
+
 	in = fopen(filename, "r");
+	free(path);
 	if (!in) {
 		printc_err("read: can't open %s: %s\n",
 			filename, last_error());

sym.c

@@ -52,11 +52,17 @@ int cmd_eval(char **arg)
 static int cmd_sym_load_add(int clear, char **arg)
 {
 	FILE *in;
+	char * path;
 
 	if (clear && prompt_abort(MODIFY_SYMS))
 		return 0;
 
-	in = fopen(*arg, "rb");
+	path = expand_tilde(*arg);
+	if (!path)
+		return -1;
+
+	in = fopen(path, "rb");
+	free(path);
 	if (!in) {
 		printc_err("sym: %s: %s\n", *arg, last_error());
 		return -1;
@@ -75,6 +81,7 @@ static int cmd_sym_load_add(int clear, char **arg)
 	}
 
 	fclose(in);
+
 	return 0;
 }
 

util.c

@@ -283,3 +283,46 @@ const char *last_error(void)
 	return strerror(errno);
 }
 #endif
+
+/* Expand leading `~/' in path names. Caller must free the returned ptr */
+char *expand_tilde(const char *path)
+{
+	char *home, *expanded;
+	size_t len;
+
+	if (!path)
+		return NULL;
+
+	if (!*path)
+		return strdup("");
+
+	expanded = NULL;
+
+	if (*path == '~' && *(path + 1) == '/') {
+		home = getenv("HOME");
+
+		if (home) {
+			/* Trailing '\0' will fit in leading '~'s place */
+			len = strlen(home) + strlen(path);
+			expanded = (char *)malloc(len);
+
+			if (expanded)
+				snprintf(expanded, len, "%s%s", home, path + 1);
+			else
+				printc_err("%s: malloc: %s\n", __FUNCTION__, last_error());
+
+		} else {
+			printc_err("%s: getenv: %s\n", __FUNCTION__, last_error());
+		}
+	} else {
+		expanded = (char *)malloc(strlen(path) + 1);
+
+		if (expanded)
+			strcpy(expanded, path);
+		else
+			printc_err("%s: malloc: %s\n", __FUNCTION__, last_error());
+	}
+
+	/* Caller must free()! */
+	return expanded;
+}

util.h

@@ -65,4 +65,7 @@ char *strsep(char **strp, const char *delim);
 HANDLE ctrlc_win32_event(void);
 #endif
 
+/* Expand `~' in path names. Caller must free the returned ptr */
+char *expand_tilde(const char *path);
+
 #endif