user/exec: shebang support

2 files changed, 21 insertions, 5 deletions

diff --git a/src/user/lib/elfload.c b/src/user/lib/elfload.c
index 6cf09c7..71714ab 100644
--- a/src/user/lib/elfload.c
+++ b/src/user/lib/elfload.c
@@ -12,7 +12,6 @@ void elf_execf(FILE *f, char **argv, char **envp) {
 	const size_t cap = 0x60000;
 	size_t pos = 0;
 	void *buf = malloc(cap); // TODO a way to get file size
-	fseek(f, 0, SEEK_SET);
 
 	if (buf && fread(buf, 1, cap - pos, f))
 		elf_exec(buf, argv, envp);
diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 0795d3d..11ca7b6 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -1,6 +1,7 @@
 #include <camellia/syscalls.h>
 #include <errno.h>
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 #include <user/lib/elfload.h>
 
@@ -19,14 +20,30 @@ _Noreturn void exit(int c) {
 }
 
 int execv(const char *path, char *const argv[]) {
-	(void)argv;
-
 	FILE *file = fopen(path, "r");
+	char hdr[4] = {0};
 	if (!file)
 		return -1;
 
-	elf_execf(file, (void*)argv, NULL);
-	fclose(file);
+	fread(hdr, 1, 4, file);
+	fseek(file, 0, SEEK_SET);
+
+	if (!memcmp("\x7f""ELF", hdr, 4)) {
+		elf_execf(file, (void*)argv, NULL);
+		fclose(file);
+	} else if (!memcmp("#!", hdr, 2)) {
+		char buf[256];
+		fseek(file, 2, SEEK_SET);
+		if (fgets(buf, sizeof buf, file)) {
+			const char *argv [] = {buf, path, NULL};
+			// TODO strchr
+			char *s = buf;
+			while (*s && *s != '\n') s++;
+			*s = '\0';
+			execv(argv[0], (void*)argv);
+		}
+	}
+
 	errno = EINVAL;
 	return -1;
 }