diff options
Diffstat (limited to 'src/cmd/shell/shell.c')
| -rw-r--r-- | src/cmd/shell/shell.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/cmd/shell/shell.c b/src/cmd/shell/shell.c new file mode 100644 index 0000000..185aa7e --- /dev/null +++ b/src/cmd/shell/shell.c @@ -0,0 +1,178 @@ +#include "builtins.h" +#include "shell.h" +#include <camellia/flags.h> +#include <camellia/syscalls.h> +#include <err.h> +#include <errno.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <camellia/fs/misc.h> +#include <x86intrin.h> + +int main(); + +static void execp(char **argv) { + if (!argv || !*argv) return; + if (strncmp(argv[0], "/", 1) == 0 || + strncmp(argv[0], "./", 2) == 0 || + strncmp(argv[0], "../", 3) == 0) + { + execv(argv[0], argv); + } else { + size_t cmdlen = strlen(argv[0]); + char *s = malloc(cmdlen + 6); + if (!s) err(1, "malloc"); + memcpy(s, "/bin/", 5); + memcpy(s + 5, argv[0], cmdlen + 1); + 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) { + fprintf(stderr, "mount: not enough arguments\n"); + return; + } + MOUNT_AT("/") { + fs_dirinject(argv[1]); + } + MOUNT_AT(argv[1]) { + run_args(argc - 2, argv + 2, redir); + exit(1); + } + return; + } else if (!strcmp(argv[0], "shadow")) { + if (argc < 2) { + fprintf(stderr, "shadow: missing path\n"); + } else { + _sys_mount(HANDLE_NULLFS, argv[1], strlen(argv[1])); + } + } else if (!strcmp(argv[0], "procmnt")) { + if (argc < 2) { + fprintf(stderr, "procmnt: missing mountpoint\n"); + return; + } + _sys_mount(HANDLE_PROCFS, argv[1], strlen(argv[1])); + /* + if (!(3 <= argc && !strcmp(argv[2], "raw"))) { + if (!mount_at("/")) { + fs_dirinject(argv[1]); + 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("%lu ns (assuming 3GHz)\n", time / div); + return; + } else if (!strcmp(argv[0], "exit")) { + exit(0); + } else if (!strcmp(argv[0], "getpid")) { + printf("my\t%d\nparent\t%d\n", getpid(), getppid()); + return; + } + + if (fork()) { + _sys_await(); + return; + } + + if (redir && redir->stdout) { + FILE *f = fopen(redir->stdout, redir->append ? "a" : "w"); + if (!f) { + err(1, "couldn't open %s for redirection", redir->stdout); + } + + /* a workaround for file offsets not being preserved across exec()s. + * TODO document that weird behaviour of exec() */ + hid_t p[2]; + if (_sys_pipe(p, 0) < 0) { + errx(1, "couldn't create redirection pipe"); + } + if (!_sys_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) err(1, "when redirecting"); + close(p[1]); + for (;;) { + long len = _sys_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 (_sys_dup(p[1], 1, 0) < 0) { + errx(1, "dup() failed when redirecting"); + } + } + + for (struct builtin *iter = builtins; iter->name; iter++) { + if (!strcmp(argv[0], iter->name)) { + setprogname(argv[0]); + iter->fn(argc, argv); + exit(0); + } + } + + execp(argv); + if (errno == EINVAL) { + errx(1, "%s isn't a valid executable", argv[0]); + } else { + errx(1, "unknown command: %s", argv[0]); + } +} + +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) { + warn("parsing error"); + } else { + 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) { + err(1, "couldn't open %s", argv[1]); + return 1; + } + } + + for (;;) { + if (f == stdin) { + printf("%s $ ", getcwd(buf, sizeof buf)); + } + if (!fgets(buf, 256, f)) { + return 0; + } + run(buf); + } +} |