[thirdparty/git.git] / compat / terminal.c

#include "git-compat-util.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(void);

static void restore_term_on_signal(int sig)
{
	restore_term();
	sigchain_pop(sig);
	raise(sig);
}

#ifdef HAVE_DEV_TTY

#define INPUT_PATH "/dev/tty"
#define OUTPUT_PATH "/dev/tty"

static int term_fd = -1;
static struct termios old_term;

static void restore_term(void)
{
	if (term_fd < 0)
		return;

	tcsetattr(term_fd, TCSAFLUSH, &old_term);
	close(term_fd);
	term_fd = -1;
}

static int disable_bits(tcflag_t bits)
{
	struct termios t;

	term_fd = open("/dev/tty", O_RDWR);
	if (tcgetattr(term_fd, &t) < 0)
		goto error;

	old_term = t;
	sigchain_push_common(restore_term_on_signal);

	t.c_lflag &= ~bits;
	if (!tcsetattr(term_fd, TCSAFLUSH, &t))
		return 0;

error:
	close(term_fd);
	term_fd = -1;
	return -1;
}

static int disable_echo(void)
{
	return disable_bits(ECHO);
}

static int enable_non_canonical(void)
{
	return disable_bits(ICANON | ECHO);
}

#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 DWORD cmode;

static 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;
	}

	if (hconin == INVALID_HANDLE_VALUE)
		return;

	SetConsoleMode(hconin, cmode);
	CloseHandle(hconin);
	hconin = INVALID_HANDLE_VALUE;
}

static int disable_bits(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");
			strvec_push(&cp.args, "-icanon");
		}

		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;
	}

	hconin = CreateFile("CONIN$", GENERIC_READ | GENERIC_WRITE,
	    FILE_SHARE_READ, NULL, OPEN_EXISTING,
	    FILE_ATTRIBUTE_NORMAL, NULL);
	if (hconin == INVALID_HANDLE_VALUE)
		return -1;

	GetConsoleMode(hconin, &cmode);
	sigchain_push_common(restore_term_on_signal);
	if (!SetConsoleMode(hconin, cmode & ~bits)) {
		CloseHandle(hconin);
		hconin = INVALID_HANDLE_VALUE;
		return -1;
	}

	return 0;
}

static int disable_echo(void)
{
	return disable_bits(ENABLE_ECHO_INPUT);
}

static int enable_non_canonical(void)
{
	return disable_bits(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

#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()) {
		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,
			      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() < 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)) {
			struct pollfd pfd = { .fd = 0, .events = POLLIN };

			if (poll(&pfd, 1, 500) < 1)
				break;

			ch = getchar();
			if (ch == EOF)
				return 0;
			strbuf_addch(buf, ch);
		}
	}

	restore_term();
	return 0;
}

#else

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
Commit	Line	Data
21aeafce JK	1	#include "git-compat-util.h"
	2	#include "compat/terminal.h"
	3	#include "sigchain.h"
	4	#include "strbuf.h"
9ea416cb JS	5	#include "run-command.h"
9ea416cb JS	6	#include "string-list.h"
12acdf57	7	#include "hashmap.h"
21aeafce	8
380395d0	9	#if defined(HAVE_DEV_TTY) \|\| defined(GIT_WINDOWS_NATIVE)
afb43561 EFL	10
	11	static void restore_term(void);
	12
	13	static void restore_term_on_signal(int sig)
	14	{
	15	restore_term();
	16	sigchain_pop(sig);
	17	raise(sig);
	18	}
	19
21aeafce JK	20	#ifdef HAVE_DEV_TTY
21aeafce JK	21
afb43561 EFL	22	#define INPUT_PATH "/dev/tty"
	23	#define OUTPUT_PATH "/dev/tty"
	24
21aeafce JK	25	static int term_fd = -1;
	26	static struct termios old_term;
	27
	28	static void restore_term(void)
	29	{
	30	if (term_fd < 0)
	31	return;
	32
	33	tcsetattr(term_fd, TCSAFLUSH, &old_term);
9df92e63	34	close(term_fd);
21aeafce JK	35	term_fd = -1;
	36	}
	37
94ac3c31	38	static int disable_bits(tcflag_t bits)
9df92e63 EFL	39	{
	40	struct termios t;
	41
	42	term_fd = open("/dev/tty", O_RDWR);
	43	if (tcgetattr(term_fd, &t) < 0)
	44	goto error;
	45
	46	old_term = t;
	47	sigchain_push_common(restore_term_on_signal);
	48
94ac3c31	49	t.c_lflag &= ~bits;
9df92e63 EFL	50	if (!tcsetattr(term_fd, TCSAFLUSH, &t))
	51	return 0;
	52
	53	error:
	54	close(term_fd);
	55	term_fd = -1;
	56	return -1;
	57	}
	58
94ac3c31 JS	59	static int disable_echo(void)
	60	{
	61	return disable_bits(ECHO);
	62	}
	63
a5e46e6b JS	64	static int enable_non_canonical(void)
	65	{
	66	return disable_bits(ICANON \| ECHO);
	67	}
	68
380395d0	69	#elif defined(GIT_WINDOWS_NATIVE)
afb43561 EFL	70
	71	#define INPUT_PATH "CONIN$"
	72	#define OUTPUT_PATH "CONOUT$"
	73	#define FORCE_TEXT "t"
	74
9ea416cb JS	75	static int use_stty = 1;
9ea416cb JS	76	static struct string_list stty_restore = STRING_LIST_INIT_DUP;
afb43561 EFL	77	static HANDLE hconin = INVALID_HANDLE_VALUE;
	78	static DWORD cmode;
	79
	80	static void restore_term(void)
	81	{
9ea416cb JS	82	if (use_stty) {
	83	int i;
	84	struct child_process cp = CHILD_PROCESS_INIT;
	85
	86	if (stty_restore.nr == 0)
	87	return;
	88
ef8d7ac4	89	strvec_push(&cp.args, "stty");
9ea416cb	90	for (i = 0; i < stty_restore.nr; i++)
ef8d7ac4	91	strvec_push(&cp.args, stty_restore.items[i].string);
9ea416cb JS	92	run_command(&cp);
	93	string_list_clear(&stty_restore, 0);
	94	return;
	95	}
	96
afb43561 EFL	97	if (hconin == INVALID_HANDLE_VALUE)
	98	return;
	99
	100	SetConsoleMode(hconin, cmode);
	101	CloseHandle(hconin);
	102	hconin = INVALID_HANDLE_VALUE;
	103	}
	104
94ac3c31	105	static int disable_bits(DWORD bits)
afb43561	106	{
9ea416cb JS	107	if (use_stty) {
	108	struct child_process cp = CHILD_PROCESS_INIT;
	109
ef8d7ac4	110	strvec_push(&cp.args, "stty");
9ea416cb JS	111
	112	if (bits & ENABLE_LINE_INPUT) {
	113	string_list_append(&stty_restore, "icanon");
ef8d7ac4	114	strvec_push(&cp.args, "-icanon");
9ea416cb JS	115	}
	116
	117	if (bits & ENABLE_ECHO_INPUT) {
	118	string_list_append(&stty_restore, "echo");
ef8d7ac4	119	strvec_push(&cp.args, "-echo");
9ea416cb JS	120	}
	121
	122	if (bits & ENABLE_PROCESSED_INPUT) {
	123	string_list_append(&stty_restore, "-ignbrk");
	124	string_list_append(&stty_restore, "intr");
	125	string_list_append(&stty_restore, "^c");
ef8d7ac4 JK	126	strvec_push(&cp.args, "ignbrk");
	127	strvec_push(&cp.args, "intr");
	128	strvec_push(&cp.args, "");
9ea416cb JS	129	}
	130
	131	if (run_command(&cp) == 0)
	132	return 0;
	133
	134	/* `stty` could not be executed; access the Console directly */
	135	use_stty = 0;
	136	}
	137
afb43561 EFL	138	hconin = CreateFile("CONIN$", GENERIC_READ \| GENERIC_WRITE,
	139	FILE_SHARE_READ, NULL, OPEN_EXISTING,
	140	FILE_ATTRIBUTE_NORMAL, NULL);
	141	if (hconin == INVALID_HANDLE_VALUE)
	142	return -1;
	143
	144	GetConsoleMode(hconin, &cmode);
	145	sigchain_push_common(restore_term_on_signal);
94ac3c31	146	if (!SetConsoleMode(hconin, cmode & ~bits)) {
afb43561 EFL	147	CloseHandle(hconin);
	148	hconin = INVALID_HANDLE_VALUE;
	149	return -1;
	150	}
	151
	152	return 0;
	153	}
	154
94ac3c31 JS	155	static int disable_echo(void)
	156	{
	157	return disable_bits(ENABLE_ECHO_INPUT);
	158	}
	159
a5e46e6b JS	160	static int enable_non_canonical(void)
	161	{
	162	return disable_bits(ENABLE_ECHO_INPUT \| ENABLE_LINE_INPUT \| ENABLE_PROCESSED_INPUT);
	163	}
94ac3c31	164
e118f063 JS	165	/*
	166	* Override `getchar()`, as the default implementation does not use
	167	* `ReadFile()`.
	168	*
	169	* This poses a problem when we want to see whether the standard
	170	* input has more characters, as the default of Git for Windows is to start the
	171	* Bash in a MinTTY, which uses a named pipe to emulate a pty, in which case
	172	* our `poll()` emulation calls `PeekNamedPipe()`, which seems to require
	173	* `ReadFile()` to be called first to work properly (it only reports 0
	174	* available bytes, otherwise).
	175	*
	176	* So let's just override `getchar()` with a version backed by `ReadFile()` and
	177	* go our merry ways from here.
	178	*/
	179	static int mingw_getchar(void)
	180	{
	181	DWORD read = 0;
	182	unsigned char ch;
	183
	184	if (!ReadFile(GetStdHandle(STD_INPUT_HANDLE), &ch, 1, &read, NULL))
	185	return EOF;
	186
	187	if (!read) {
	188	error("Unexpected 0 read");
	189	return EOF;
	190	}
	191
	192	return ch;
	193	}
	194	#define getchar mingw_getchar
	195
afb43561 EFL	196	#endif
	197
	198	#ifndef FORCE_TEXT
	199	#define FORCE_TEXT
	200	#endif
	201
21aeafce JK	202	char git_terminal_prompt(const char prompt, int echo)
	203	{
	204	static struct strbuf buf = STRBUF_INIT;
	205	int r;
67fe7356	206	FILE input_fh, output_fh;
21aeafce	207
afb43561	208	input_fh = fopen(INPUT_PATH, "r" FORCE_TEXT);
67fe7356	209	if (!input_fh)
21aeafce JK	210	return NULL;
21aeafce JK	211
afb43561	212	output_fh = fopen(OUTPUT_PATH, "w" FORCE_TEXT);
67fe7356 EFL	213	if (!output_fh) {
	214	fclose(input_fh);
	215	return NULL;
	216	}
	217
9df92e63	218	if (!echo && disable_echo()) {
67fe7356 EFL	219	fclose(input_fh);
67fe7356 EFL	220	fclose(output_fh);
9df92e63	221	return NULL;
21aeafce JK	222	}
21aeafce JK	223
67fe7356 EFL	224	fputs(prompt, output_fh);
67fe7356 EFL	225	fflush(output_fh);
21aeafce	226
8f309aeb	227	r = strbuf_getline_lf(&buf, input_fh);
21aeafce	228	if (!echo) {
67fe7356 EFL	229	putc('\n', output_fh);
67fe7356 EFL	230	fflush(output_fh);
21aeafce JK	231	}
	232
	233	restore_term();
67fe7356 EFL	234	fclose(input_fh);
67fe7356 EFL	235	fclose(output_fh);
21aeafce JK	236
	237	if (r == EOF)
	238	return NULL;
	239	return buf.buf;
	240	}
	241
12acdf57 JS	242	/*
	243	* The `is_known_escape_sequence()` function returns 1 if the passed string
	244	* corresponds to an Escape sequence that the terminal capabilities contains.
	245	*
	246	* To avoid depending on ncurses or other platform-specific libraries, we rely
	247	* on the presence of the `infocmp` executable to do the job for us (failing
	248	* silently if the program is not available or refused to run).
	249	*/
	250	struct escape_sequence_entry {
	251	struct hashmap_entry entry;
	252	char sequence[FLEX_ARRAY];
	253	};
	254
	255	static int sequence_entry_cmp(const void *hashmap_cmp_fn_data,
	256	const struct escape_sequence_entry *e1,
	257	const struct escape_sequence_entry *e2,
	258	const void *keydata)
	259	{
	260	return strcmp(e1->sequence, keydata ? keydata : e2->sequence);
	261	}
	262
	263	static int is_known_escape_sequence(const char *sequence)
	264	{
	265	static struct hashmap sequences;
	266	static int initialized;
	267
	268	if (!initialized) {
	269	struct child_process cp = CHILD_PROCESS_INIT;
	270	struct strbuf buf = STRBUF_INIT;
	271	char p, eol;
	272
	273	hashmap_init(&sequences, (hashmap_cmp_fn)sequence_entry_cmp,
	274	NULL, 0);
	275
ef8d7ac4	276	strvec_pushl(&cp.args, "infocmp", "-L", "-1", NULL);
12acdf57 JS	277	if (pipe_command(&cp, NULL, 0, &buf, 0, NULL, 0))
	278	strbuf_setlen(&buf, 0);
	279
	280	for (eol = p = buf.buf; *p; p = eol + 1) {
	281	p = strchr(p, '=');
	282	if (!p)
	283	break;
	284	p++;
	285	eol = strchrnul(p, '\n');
	286
	287	if (starts_with(p, "\\E")) {
	288	char *comma = memchr(p, ',', eol - p);
	289	struct escape_sequence_entry *e;
	290
	291	p[0] = '^';
	292	p[1] = '[';
	293	FLEX_ALLOC_MEM(e, sequence, p, comma - p);
	294	hashmap_entry_init(&e->entry,
	295	strhash(e->sequence));
	296	hashmap_add(&sequences, &e->entry);
	297	}
	298	if (!*eol)
	299	break;
	300	}
	301	initialized = 1;
	302	}
	303
	304	return !!hashmap_get_from_hash(&sequences, strhash(sequence), sequence);
	305	}
	306
a5e46e6b JS	307	int read_key_without_echo(struct strbuf *buf)
	308	{
	309	static int warning_displayed;
	310	int ch;
	311
	312	if (warning_displayed \|\| enable_non_canonical() < 0) {
	313	if (!warning_displayed) {
	314	warning("reading single keystrokes not supported on "
	315	"this platform; reading line instead");
	316	warning_displayed = 1;
	317	}
	318
	319	return strbuf_getline(buf, stdin);
	320	}
	321
	322	strbuf_reset(buf);
	323	ch = getchar();
	324	if (ch == EOF) {
	325	restore_term();
	326	return EOF;
	327	}
a5e46e6b	328	strbuf_addch(buf, ch);
e118f063 JS	329
	330	if (ch == '\033' /* ESC */) {
	331	/*
	332	* We are most likely looking at an Escape sequence. Let's try
	333	* to read more bytes, waiting at most half a second, assuming
	334	* that the sequence is complete if we did not receive any byte
	335	* within that time.
	336	*
	337	* Start by replacing the Escape byte with ^[ */
	338	strbuf_splice(buf, buf->len - 1, 1, "^[", 2);
	339
12acdf57 JS	340	/*
	341	* Query the terminal capabilities once about all the Escape
	342	* sequences it knows about, so that we can avoid waiting for
	343	* half a second when we know that the sequence is complete.
	344	*/
	345	while (!is_known_escape_sequence(buf->buf)) {
e118f063 JS	346	struct pollfd pfd = { .fd = 0, .events = POLLIN };
	347
	348	if (poll(&pfd, 1, 500) < 1)
	349	break;
	350
	351	ch = getchar();
	352	if (ch == EOF)
	353	return 0;
	354	strbuf_addch(buf, ch);
	355	}
	356	}
	357
a5e46e6b JS	358	restore_term();
	359	return 0;
	360	}
	361
21aeafce JK	362	#else
	363
	364	char git_terminal_prompt(const char prompt, int echo)
	365	{
	366	return getpass(prompt);
	367	}
	368
a5e46e6b JS	369	int read_key_without_echo(struct strbuf *buf)
	370	{
	371	static int warning_displayed;
	372	const char *res;
	373
	374	if (!warning_displayed) {
	375	warning("reading single keystrokes not supported on this "
	376	"platform; reading line instead");
	377	warning_displayed = 1;
	378	}
	379
	380	res = getpass("");
	381	strbuf_reset(buf);
	382	if (!res)
	383	return EOF;
	384	strbuf_addstr(buf, res);
	385	return 0;
	386	}
	387
21aeafce	388	#endif