commit 78fa4a58eb5dc9d0db50659bfaa6f59b7313c512
parent 26ea86ba3aca1f176e6cd862385dfea91e991a5d
Author: mjkloeckner <martin.cachari@gmail.com>
Date: Sun, 14 May 2023 00:04:34 -0300
add support for built-in functions
Diffstat:
| M | msh.c | | | 51 | ++++++++++++++++++++++++++++++++++++++++++++++++--- |
1 file changed, 48 insertions(+), 3 deletions(-)
diff --git a/msh.c b/msh.c
@@ -5,6 +5,7 @@
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <pwd.h>
#include <ctype.h>
@@ -19,6 +20,13 @@
static bool run = true;
static size_t buffer_alloc;
static size_t tokens_alloc;
+static size_t builtin_index;
+
+static const char *msh_builtins_name[] = {
+ "cd"
+};
+
+#define TOTAL_BUILTINS sizeof(msh_builtins_name)/sizeof(msh_builtins_name[0])
void buffer_print_slice(const char *buf, size_t from, size_t to) {
for(size_t i = from; i < to; i++)
@@ -197,6 +205,39 @@ char *editor_read_line(char *s) {
return s;
}
+bool is_builtin(const char *name) {
+ size_t i;
+ for(i = builtin_index = 0; i < TOTAL_BUILTINS; i++)
+ if(!strcmp(name, msh_builtins_name[i]))
+ return true;
+
+ return false;
+}
+
+void msh_cd(const char **path) {
+ if(path[1] == NULL) {
+ /* go ot user home */
+ struct passwd *pw = getpwuid(getuid());
+ const char *user_home_dir = pw->pw_dir;
+ if(chdir(user_home_dir) < 0) {
+ perror("cd");
+ }
+ }
+ else {
+ if(chdir(path[1]) < 0)
+ fprintf(stderr,
+ "%s: No usch file or directory: %s\n",
+ "cd", path[0]);
+ }
+}
+
+static void (*msh_builtin_handler[])(const char **argv) = {
+ &msh_cd,
+};
+
+void msh_execute_builtin(char **argv) {
+ msh_builtin_handler[builtin_index]((const char **)argv);
+}
void msh_execute(char **argv) {
int status;
@@ -245,9 +286,13 @@ void msh_loop(void) {
tokens = buffer_split(buffer, tokens);
/* skip execute if buffer is empty */
- if(strlen(buffer) > 0)
- msh_execute(tokens);
-
+ if(strlen(buffer) > 0) {
+ if(is_builtin(tokens[0]))
+ msh_execute_builtin(tokens);
+ else
+ msh_execute(tokens);
+ }
+
buffer_clear(buffer);
}
free(tokens);
