diff options
Diffstat (limited to 'src/user/app/shell')
| -rw-r--r-- | src/user/app/shell/shell.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/user/app/shell/shell.c b/src/user/app/shell/shell.c new file mode 100644 index 0000000..9c51aeb --- /dev/null +++ b/src/user/app/shell/shell.c @@ -0,0 +1,213 @@ +#include <camellia/syscalls.h> +#include <errno.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +static bool isspace(char c) { + return c == ' ' || c == '\t' || c == '\n'; +} + +static char *strsplit(char *base, char delim) { + if (!base) return NULL; + while (*base) { + if (delim ? *base == delim : isspace(*base)) { + *base++ = '\0'; + return base; + } + base++; + } + return NULL; +} + +static char *strtrim(char *s) { + char *end; + if (!s) return NULL; + while (isspace(*s)) s++; + end = s + strlen(s); + while (end > s && isspace(end[-1])) end--; + *end = '\0'; + return s; +} + + +// TODO fgets +static int readline(char *buf, size_t max) { + char c = '\0'; + size_t pos = 0; + while (pos < (max-1) && c != '\n' && fread(&c, 1, 1, stdin)) + buf[pos++] = c; + buf[pos++] = '\0'; + return pos; +} + +static void cmd_cat_ls(const char *args, bool ls) { + FILE *file; + static char buf[512]; + int len; // first used for strlen(args), then length of buffer + + if (args) { + len = strlen(args); + memcpy(buf, args, len + 1); // no overflow check - the shell is just a PoC + + if (ls) { // paths to directories always have a trailing slash + if (buf[len-1] != '/') { + buf[len] = '/'; + buf[len+1] = '\0'; + } + } + + file = fopen(buf, "r"); + } else if (ls) { /* ls default argument */ + file = fopen("/", "r"); + } else { /* cat default argument */ + file = file_clone(stdin); + } + + if (!file) { + printf("couldn't open.\n"); + return; + } + + while (!feof(file)) { + int len = fread(buf, 1, sizeof buf, file); + if (len <= 0) break; + + if (ls) { + for (int i = 0; i < len; i++) + if (buf[i] == '\0') buf[i] = '\n'; + } + fwrite(buf, 1, len, stdout); + } + fclose(file); +} + +static void cmd_hexdump(const char *args) { + static uint8_t buf[512]; + int fd, len; + + fd = _syscall_open(args, strlen(args), 0); + if (fd < 0) { + printf("couldn't open.\n"); + return; + } + + len = _syscall_read(fd, buf, sizeof buf, 0); + for (int i = 0; i < len; i += 16) { + printf("%08x ", i); + + for (int j = i; j < i + 8 && j < len; j++) + printf("%02x ", buf[j]); + printf(" "); + for (int j = i + 8; j < i + 16 && j < len; j++) + printf("%02x ", buf[j]); + printf(" |"); + + for (int j = i; j < i + 16 && j < len; j++) { + char c = '.'; + if (0x20 <= buf[j] && buf[j] < 0x7f) c = buf[j]; + printf("%c", c); + } + printf("|\n"); + } + + close(fd); +} + +static void cmd_touch(const char *args) { + int fd = _syscall_open(args, strlen(args), OPEN_CREATE); + if (fd < 0) { + printf("couldn't create file.\n"); + return; + } + close(fd); +} + +int main(void) { + static char buf[256]; + int level = 0; + char *cmd, *args, *redir; + + for (;;) { + printf("%x$ ", level); + + readline(buf, 256); + if (feof(stdin)) + return 0; + + cmd = strtrim(buf); + if (!*cmd) continue; + + redir = strtrim(strsplit(cmd, '>')); + cmd = strtrim(cmd); + args = strtrim(strsplit(cmd, 0)); + + /* "special" commands that can't be handled in a subprocess */ + if (!strcmp(cmd, "shadow")) { + _syscall_mount(-1, args, strlen(args)); + continue; + } else if (!strcmp(cmd, "exit")) { + return 0; + } else if (!strcmp(cmd, "fork")) { + if (!fork()) level++; + else _syscall_await(); + continue; + } + + if (!fork()) { + if (redir && !freopen(redir, "w", stdout)) { + // TODO stderr + exit(0); + } + + if (!strcmp(cmd, "echo")) { + printf("%s\n", args); + } else if (!strcmp(cmd, "cat")) { + cmd_cat_ls(args, false); + } else if (!strcmp(cmd, "ls")) { + cmd_cat_ls(args, true); + } else if (!strcmp(cmd, "hexdump")) { + cmd_hexdump(args); + } else if (!strcmp(cmd, "catall")) { + const char *files[] = { + "/init/fake.txt", + "/init/1.txt", "/init/2.txt", + "/init/dir/3.txt", NULL}; + for (int i = 0; files[i]; i++) { + printf("%s:\n", files[i]); + cmd_cat_ls(files[i], false); + printf("\n"); + } + } else if (!strcmp(cmd, "touch")) { + cmd_touch(args); + } else { + char *binname = cmd; + if (*cmd != '/') { + size_t cmdlen = strlen(cmd); + binname = malloc(cmdlen); + if (!binname) { + printf("sh: out of memory.\n"); + exit(1); + } + memcpy(binname, "/bin/", 5); + memcpy(binname + 5, cmd, cmdlen + 1); + } + + execv(binname, NULL); + if (errno == EINVAL) { + printf("%s isn't a valid executable\n", cmd); + } else { + printf("unknown command: %s\n", cmd); + } + + if (binname != cmd) + free(binname); + } + exit(0); + } else { + _syscall_await(); + } + } +} |