shell: separate code

source/shell/cmd.c

@@ -0,0 +1,81 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <shell.h>
+
+struct cmd main_cmds[] = {
+	{ "flash", do_flash_cmd },
+	{ NULL, NULL },
+};
+
+static char *prompt(const char *prefix)
+{
+	char *alloc, *line, *s;
+	size_t nbytes = 0, nalloc_bytes = 16;
+	char c;
+
+	printf(prefix);
+
+	if (!(line = malloc(nalloc_bytes)))
+		return NULL;
+
+	s = line;
+
+	while ((c = getchar()) && c != '\n') {
+		putchar(c);
+
+		if (nbytes + 1 >= nalloc_bytes) {
+			nalloc_bytes *= 2;
+
+			if (!(alloc = realloc(line, nalloc_bytes)))
+				goto err_free_line;
+
+			line = alloc;
+		}
+
+		*s++ = c;
+		nbytes++;
+	}
+
+	printf("\n");
+	*s = '\0';
+
+	return line;
+
+err_free_line:
+	free(line);
+	return NULL;
+}
+
+void cmd_exec(struct cmd *cmds, const char *line)
+{
+	struct cmd *cmd;
+	const char *args;
+	char *key;
+	size_t n;
+
+	n = strcspn(line, " \n");
+	key = strndup(line, n);
+
+	args = line + n;
+	args += strspn(args, " \n");
+
+	for (cmd = cmds; cmd->key; ++cmd) {
+		if (strcmp(cmd->key, key) == 0) {
+			cmd->exec(args);
+			return;
+		}
+	}
+}
+
+void cmd_loop(const char *show)
+{
+	char *line;
+
+	while (1) {
+		line = prompt(show);
+		cmd_exec(main_cmds, line);
+		free(line);
+	}
+}