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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
commitc8bae7493d2f2910b57f13ded012e86bdcfb0532 (patch)
tree24e09d9f84dec336720cf393e156089ca2835791 /compat/terminal.c
parentInitial commit. (diff)
downloadgit-upstream.tar.xz
git-upstream.zip
Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--compat/terminal.c618
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