diff options
Diffstat (limited to 'compat/terminal.c')
| -rw-r--r-- | compat/terminal.c | 618 |
1 files changed, 618 insertions, 0 deletions
diff --git a/compat/terminal.c b/compat/terminal.c new file mode 100644 index 0000000..ea490a7 --- /dev/null +++ b/compat/terminal.c @@ -0,0 +1,618 @@ +#include "cache.h" +#include "compat/terminal.h" +#include "sigchain.h" +#include "strbuf.h" +#include "run-command.h" +#include "string-list.h" +#include "hashmap.h" + +#if defined(HAVE_DEV_TTY) || defined(GIT_WINDOWS_NATIVE) + +static void restore_term_on_signal(int sig) +{ + restore_term(); + /* restore_term calls sigchain_pop_common */ + raise(sig); +} + +#ifdef HAVE_DEV_TTY + +#define INPUT_PATH "/dev/tty" +#define OUTPUT_PATH "/dev/tty" + +static volatile sig_atomic_t term_fd_needs_closing; +static int term_fd = -1; +static struct termios old_term; + +static const char *background_resume_msg; +static const char *restore_error_msg; +static volatile sig_atomic_t ttou_received; + +/* async safe error function for use by signal handlers. */ +static void write_err(const char *msg) +{ + write_in_full(2, "error: ", strlen("error: ")); + write_in_full(2, msg, strlen(msg)); + write_in_full(2, "\n", 1); +} + +static void print_background_resume_msg(int signo) +{ + int saved_errno = errno; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + + ttou_received = 1; + write_err(background_resume_msg); + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + errno = saved_errno; +} + +static void restore_terminal_on_suspend(int signo) +{ + int saved_errno = errno; + int res; + struct termios t; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + int can_restore = 1; + + if (tcgetattr(term_fd, &t) < 0) + can_restore = 0; + + if (tcsetattr(term_fd, TCSAFLUSH, &old_term) < 0) + write_err(restore_error_msg); + + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + if (!can_restore) { + write_err(restore_error_msg); + goto out; + } + /* + * If we resume in the background then we receive SIGTTOU when calling + * tcsetattr() below. Set up a handler to print an error message in that + * case. + */ + sigemptyset(&mask); + sigaddset(&mask, SIGTTOU); + sa.sa_mask = old_sa.sa_mask; + sa.sa_handler = print_background_resume_msg; + sa.sa_flags = SA_RESTART; + sigaction(SIGTTOU, &sa, &old_sa); + again: + ttou_received = 0; + sigprocmask(SIG_UNBLOCK, &mask, NULL); + res = tcsetattr(term_fd, TCSAFLUSH, &t); + sigprocmask(SIG_BLOCK, &mask, NULL); + if (ttou_received) + goto again; + else if (res < 0) + write_err(restore_error_msg); + sigaction(SIGTTOU, &old_sa, NULL); + out: + errno = saved_errno; +} + +static void reset_job_signals(void) +{ + if (restore_error_msg) { + signal(SIGTTIN, SIG_DFL); + signal(SIGTTOU, SIG_DFL); + signal(SIGTSTP, SIG_DFL); + restore_error_msg = NULL; + background_resume_msg = NULL; + } +} + +static void close_term_fd(void) +{ + if (term_fd_needs_closing) + close(term_fd); + term_fd_needs_closing = 0; + term_fd = -1; +} + +void restore_term(void) +{ + if (term_fd < 0) + return; + + tcsetattr(term_fd, TCSAFLUSH, &old_term); + close_term_fd(); + sigchain_pop_common(); + reset_job_signals(); +} + +int save_term(enum save_term_flags flags) +{ + struct sigaction sa; + + if (term_fd < 0) + term_fd = ((flags & SAVE_TERM_STDIN) + ? 0 + : open("/dev/tty", O_RDWR)); + if (term_fd < 0) + return -1; + term_fd_needs_closing = !(flags & SAVE_TERM_STDIN); + if (tcgetattr(term_fd, &old_term) < 0) { + close_term_fd(); + return -1; + } + sigchain_push_common(restore_term_on_signal); + /* + * If job control is disabled then the shell will have set the + * disposition of SIGTSTP to SIG_IGN. + */ + sigaction(SIGTSTP, NULL, &sa); + if (sa.sa_handler == SIG_IGN) + return 0; + + /* avoid calling gettext() from signal handler */ + background_resume_msg = _("cannot resume in the background, please use 'fg' to resume"); + restore_error_msg = _("cannot restore terminal settings"); + sa.sa_handler = restore_terminal_on_suspend; + sa.sa_flags = SA_RESTART; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGTSTP); + sigaddset(&sa.sa_mask, SIGTTIN); + sigaddset(&sa.sa_mask, SIGTTOU); + sigaction(SIGTSTP, &sa, NULL); + sigaction(SIGTTIN, &sa, NULL); + sigaction(SIGTTOU, &sa, NULL); + + return 0; +} + +static int disable_bits(enum save_term_flags flags, tcflag_t bits) +{ + struct termios t; + + if (save_term(flags) < 0) + return -1; + + t = old_term; + + t.c_lflag &= ~bits; + if (bits & ICANON) { + t.c_cc[VMIN] = 1; + t.c_cc[VTIME] = 0; + } + if (!tcsetattr(term_fd, TCSAFLUSH, &t)) + return 0; + + sigchain_pop_common(); + reset_job_signals(); + close_term_fd(); + return -1; +} + +static int disable_echo(enum save_term_flags flags) +{ + return disable_bits(flags, ECHO); +} + +static int enable_non_canonical(enum save_term_flags flags) +{ + return disable_bits(flags, ICANON | ECHO); +} + +/* + * On macos it is not possible to use poll() with a terminal so use select + * instead. + */ +static int getchar_with_timeout(int timeout) +{ + struct timeval tv, *tvp = NULL; + fd_set readfds; + int res; + + again: + if (timeout >= 0) { + tv.tv_sec = timeout / 1000; + tv.tv_usec = (timeout % 1000) * 1000; + tvp = &tv; + } + + FD_ZERO(&readfds); + FD_SET(0, &readfds); + res = select(1, &readfds, NULL, NULL, tvp); + if (!res) + return EOF; + if (res < 0) { + if (errno == EINTR) + goto again; + else + return EOF; + } + return getchar(); +} + +#elif defined(GIT_WINDOWS_NATIVE) + +#define INPUT_PATH "CONIN$" +#define OUTPUT_PATH "CONOUT$" +#define FORCE_TEXT "t" + +static int use_stty = 1; +static struct string_list stty_restore = STRING_LIST_INIT_DUP; +static HANDLE hconin = INVALID_HANDLE_VALUE; +static HANDLE hconout = INVALID_HANDLE_VALUE; +static DWORD cmode_in, cmode_out; + +void restore_term(void) +{ + if (use_stty) { + int i; + struct child_process cp = CHILD_PROCESS_INIT; + + if (stty_restore.nr == 0) + return; + + strvec_push(&cp.args, "stty"); + for (i = 0; i < stty_restore.nr; i++) + strvec_push(&cp.args, stty_restore.items[i].string); + run_command(&cp); + string_list_clear(&stty_restore, 0); + return; + } + + sigchain_pop_common(); + + if (hconin == INVALID_HANDLE_VALUE) + return; + + SetConsoleMode(hconin, cmode_in); + CloseHandle(hconin); + if (cmode_out) { + assert(hconout != INVALID_HANDLE_VALUE); + SetConsoleMode(hconout, cmode_out); + CloseHandle(hconout); + } + + hconin = hconout = INVALID_HANDLE_VALUE; +} + +int save_term(enum save_term_flags flags) +{ + hconin = CreateFileA("CONIN$", GENERIC_READ | GENERIC_WRITE, + FILE_SHARE_READ, NULL, OPEN_EXISTING, + FILE_ATTRIBUTE_NORMAL, NULL); + if (hconin == INVALID_HANDLE_VALUE) + return -1; + + if (flags & SAVE_TERM_DUPLEX) { + hconout = CreateFileA("CONOUT$", GENERIC_READ | GENERIC_WRITE, + FILE_SHARE_WRITE, NULL, OPEN_EXISTING, + FILE_ATTRIBUTE_NORMAL, NULL); + if (hconout == INVALID_HANDLE_VALUE) + goto error; + + GetConsoleMode(hconout, &cmode_out); + } + + GetConsoleMode(hconin, &cmode_in); + use_stty = 0; + sigchain_push_common(restore_term_on_signal); + return 0; +error: + CloseHandle(hconin); + hconin = INVALID_HANDLE_VALUE; + return -1; +} + +static int disable_bits(enum save_term_flags flags, DWORD bits) +{ + if (use_stty) { + struct child_process cp = CHILD_PROCESS_INIT; + + strvec_push(&cp.args, "stty"); + + if (bits & ENABLE_LINE_INPUT) { + string_list_append(&stty_restore, "icanon"); + /* + * POSIX allows VMIN and VTIME to overlap with VEOF and + * VEOL - let's hope that is not the case on windows. + */ + strvec_pushl(&cp.args, "-icanon", "min", "1", "time", "0", NULL); + } + + if (bits & ENABLE_ECHO_INPUT) { + string_list_append(&stty_restore, "echo"); + strvec_push(&cp.args, "-echo"); + } + + if (bits & ENABLE_PROCESSED_INPUT) { + string_list_append(&stty_restore, "-ignbrk"); + string_list_append(&stty_restore, "intr"); + string_list_append(&stty_restore, "^c"); + strvec_push(&cp.args, "ignbrk"); + strvec_push(&cp.args, "intr"); + strvec_push(&cp.args, ""); + } + + if (run_command(&cp) == 0) + return 0; + + /* `stty` could not be executed; access the Console directly */ + use_stty = 0; + } + + if (save_term(flags) < 0) + return -1; + + if (!SetConsoleMode(hconin, cmode_in & ~bits)) { + CloseHandle(hconin); + hconin = INVALID_HANDLE_VALUE; + sigchain_pop_common(); + return -1; + } + + return 0; +} + +static int disable_echo(enum save_term_flags flags) +{ + return disable_bits(flags, ENABLE_ECHO_INPUT); +} + +static int enable_non_canonical(enum save_term_flags flags) +{ + return disable_bits(flags, + ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT); +} + +/* + * Override `getchar()`, as the default implementation does not use + * `ReadFile()`. + * + * This poses a problem when we want to see whether the standard + * input has more characters, as the default of Git for Windows is to start the + * Bash in a MinTTY, which uses a named pipe to emulate a pty, in which case + * our `poll()` emulation calls `PeekNamedPipe()`, which seems to require + * `ReadFile()` to be called first to work properly (it only reports 0 + * available bytes, otherwise). + * + * So let's just override `getchar()` with a version backed by `ReadFile()` and + * go our merry ways from here. + */ +static int mingw_getchar(void) +{ + DWORD read = 0; + unsigned char ch; + + if (!ReadFile(GetStdHandle(STD_INPUT_HANDLE), &ch, 1, &read, NULL)) + return EOF; + + if (!read) { + error("Unexpected 0 read"); + return EOF; + } + + return ch; +} +#define getchar mingw_getchar + +static int getchar_with_timeout(int timeout) +{ + struct pollfd pfd = { .fd = 0, .events = POLLIN }; + + if (poll(&pfd, 1, timeout) < 1) + return EOF; + + return getchar(); +} + +#endif + +#ifndef FORCE_TEXT +#define FORCE_TEXT +#endif + +char *git_terminal_prompt(const char *prompt, int echo) +{ + static struct strbuf buf = STRBUF_INIT; + int r; + FILE *input_fh, *output_fh; + + input_fh = fopen(INPUT_PATH, "r" FORCE_TEXT); + if (!input_fh) + return NULL; + + output_fh = fopen(OUTPUT_PATH, "w" FORCE_TEXT); + if (!output_fh) { + fclose(input_fh); + return NULL; + } + + if (!echo && disable_echo(0)) { + fclose(input_fh); + fclose(output_fh); + return NULL; + } + + fputs(prompt, output_fh); + fflush(output_fh); + + r = strbuf_getline_lf(&buf, input_fh); + if (!echo) { + putc('\n', output_fh); + fflush(output_fh); + } + + restore_term(); + fclose(input_fh); + fclose(output_fh); + + if (r == EOF) + return NULL; + return buf.buf; +} + +/* + * The `is_known_escape_sequence()` function returns 1 if the passed string + * corresponds to an Escape sequence that the terminal capabilities contains. + * + * To avoid depending on ncurses or other platform-specific libraries, we rely + * on the presence of the `infocmp` executable to do the job for us (failing + * silently if the program is not available or refused to run). + */ +struct escape_sequence_entry { + struct hashmap_entry entry; + char sequence[FLEX_ARRAY]; +}; + +static int sequence_entry_cmp(const void *hashmap_cmp_fn_data UNUSED, + const struct escape_sequence_entry *e1, + const struct escape_sequence_entry *e2, + const void *keydata) +{ + return strcmp(e1->sequence, keydata ? keydata : e2->sequence); +} + +static int is_known_escape_sequence(const char *sequence) +{ + static struct hashmap sequences; + static int initialized; + + if (!initialized) { + struct child_process cp = CHILD_PROCESS_INIT; + struct strbuf buf = STRBUF_INIT; + char *p, *eol; + + hashmap_init(&sequences, (hashmap_cmp_fn)sequence_entry_cmp, + NULL, 0); + + strvec_pushl(&cp.args, "infocmp", "-L", "-1", NULL); + if (pipe_command(&cp, NULL, 0, &buf, 0, NULL, 0)) + strbuf_setlen(&buf, 0); + + for (eol = p = buf.buf; *p; p = eol + 1) { + p = strchr(p, '='); + if (!p) + break; + p++; + eol = strchrnul(p, '\n'); + + if (starts_with(p, "\\E")) { + char *comma = memchr(p, ',', eol - p); + struct escape_sequence_entry *e; + + p[0] = '^'; + p[1] = '['; + FLEX_ALLOC_MEM(e, sequence, p, comma - p); + hashmap_entry_init(&e->entry, + strhash(e->sequence)); + hashmap_add(&sequences, &e->entry); + } + if (!*eol) + break; + } + initialized = 1; + } + + return !!hashmap_get_from_hash(&sequences, strhash(sequence), sequence); +} + +int read_key_without_echo(struct strbuf *buf) +{ + static int warning_displayed; + int ch; + + if (warning_displayed || enable_non_canonical(SAVE_TERM_STDIN) < 0) { + if (!warning_displayed) { + warning("reading single keystrokes not supported on " + "this platform; reading line instead"); + warning_displayed = 1; + } + + return strbuf_getline(buf, stdin); + } + + strbuf_reset(buf); + ch = getchar(); + if (ch == EOF) { + restore_term(); + return EOF; + } + strbuf_addch(buf, ch); + + if (ch == '\033' /* ESC */) { + /* + * We are most likely looking at an Escape sequence. Let's try + * to read more bytes, waiting at most half a second, assuming + * that the sequence is complete if we did not receive any byte + * within that time. + * + * Start by replacing the Escape byte with ^[ */ + strbuf_splice(buf, buf->len - 1, 1, "^[", 2); + + /* + * Query the terminal capabilities once about all the Escape + * sequences it knows about, so that we can avoid waiting for + * half a second when we know that the sequence is complete. + */ + while (!is_known_escape_sequence(buf->buf)) { + ch = getchar_with_timeout(500); + if (ch == EOF) + break; + strbuf_addch(buf, ch); + } + } + + restore_term(); + return 0; +} + +#else + +int save_term(enum save_term_flags flags) +{ + /* no duplex support available */ + return -!!(flags & SAVE_TERM_DUPLEX); +} + +void restore_term(void) +{ +} + +char *git_terminal_prompt(const char *prompt, int echo) +{ + return getpass(prompt); +} + +int read_key_without_echo(struct strbuf *buf) +{ + static int warning_displayed; + const char *res; + + if (!warning_displayed) { + warning("reading single keystrokes not supported on this " + "platform; reading line instead"); + warning_displayed = 1; + } + + res = getpass(""); + strbuf_reset(buf); + if (!res) + return EOF; + strbuf_addstr(buf, res); + return 0; +} + +#endif |