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#include "builtins.h"
#include "shell.h"
#include <camellia/flags.h>
#include <camellia/syscalls.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <user/lib/fs/misc.h>
#include <x86intrin.h>
int main();
static void execp(char **argv) {
if (!argv || !*argv) return;
if (argv[0][0] == '/') {
execv(argv[0], argv);
return;
}
size_t cmdlen = strlen(argv[0]);
char *s = malloc(cmdlen);
if (!s) {
eprintf("out of memory.");
exit(1);
}
memcpy(s, "/bin/", 5);
memcpy(s + 5, argv[0], cmdlen + 1);
argv[0] = s;
execv(s, argv);
free(s);
}
void run_args(int argc, char **argv, struct redir *redir) {
if (!*argv) return;
/* "special" commands that can't be handled in a subprocess */
if (!strcmp(argv[0], "mount")) {
if (argc < 3) {
eprintf("not enough arguments");
return;
}
MOUNT_AT(argv[1]) {
run_args(argc - 2, argv + 2, redir);
exit(1);
}
return;
} else if (!strcmp(argv[0], "cd")) {
if (chdir(argc > 1 ? argv[1] : "/") < 0)
perror("cd");
return;
} else if (!strcmp(argv[0], "time")) {
uint64_t time = __rdtsc();
uint64_t div = 3000;
run_args(argc - 1, argv + 1, redir);
time = __rdtsc() - time;
printf("%u ns (assuming 3GHz)\n", time / div);
return;
} else if (!strcmp(argv[0], "exit")) {
exit(0);
}
if (fork()) {
_syscall_await();
return;
}
if (redir && redir->stdout) {
FILE *f = fopen(redir->stdout, redir->append ? "a" : "w");
if (!f) {
eprintf("couldn't open %s for redirection", redir->stdout);
exit(1);
}
/* a workaround for file offsets not being preserved across exec()s.
* TODO document that weird behaviour of exec() */
handle_t p[2];
if (_syscall_pipe(p, 0) < 0) {
eprintf("couldn't create redirection pipe", redir->stdout);
exit(1);
}
if (!_syscall_fork(FORK_NOREAP, NULL)) {
/* the child forwards data from the pipe to the file */
const size_t buflen = 512;
char *buf = malloc(buflen);
if (!buf) {
eprintf("when redirecting: malloc failure");
exit(1);
}
close(p[1]);
for (;;) {
long len = _syscall_read(p[0], buf, buflen, 0);
if (len < 0) exit(0);
fwrite(buf, 1, len, f);
if (ferror(f)) exit(0);
}
}
fclose(f);
close(p[0]);
if (_syscall_dup(p[1], 1, 0) < 0) {
eprintf("dup failure");
exit(1);
}
}
for (struct builtin *iter = builtins; iter->name; iter++) {
if (!strcmp(argv[0], iter->name)) {
iter->fn(argc, argv);
exit(0);
}
}
execp(argv);
if (errno == EINVAL) {
eprintf("%s isn't a valid executable\n", argv[0]);
} else {
eprintf("unknown command: %s\n", argv[0]);
}
exit(0); /* kills the subprocess */
}
static void run(char *cmd) {
#define ARGV_MAX 16
char *argv[ARGV_MAX];
struct redir redir;
int argc = parse(cmd, argv, ARGV_MAX, &redir);
if (argc < 0) {
eprintf("error parsing command");
return;
}
run_args(argc, argv, &redir);
}
int main(int argc, char **argv) {
static char buf[256];
FILE *f = stdin;
if (argc > 1) {
f = fopen(argv[1], "r");
if (!f) {
eprintf("couldn't open %s\n", argv[1]);
return 1;
}
}
for (;;) {
if (f == stdin)
printf("%s $ ", getcwd(buf, sizeof buf));
if (!fgets(buf, 256, f))
return 0;
run(buf);
}
}
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