git/compat/terminal.c
Johannes Schindelin 9ea416cb51 terminal: accommodate Git for Windows' default terminal
Git for Windows' Git Bash runs in MinTTY by default, which does not have
a Win32 Console instance, but uses MSYS2 pseudo terminals instead.

This is a problem, as Git for Windows does not want to use the MSYS2
emulation layer for Git itself, and therefore has no direct way to
interact with that pseudo terminal.

As a workaround, use the `stty` utility (which is included in Git for
Windows, and which *is* an MSYS2 program, so it knows how to deal with
the pseudo terminal).

Note: If Git runs in a regular CMD or PowerShell window, there *is* a
regular Win32 Console to work with. This is not a problem for the MSYS2
`stty`: it copes with this scenario just fine.

Also note that we introduce support for more bits than would be
necessary for a mere `disable_echo()` here, in preparation for the
upcoming `enable_non_canonical()` function.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00

209 lines
3.8 KiB
C

#include "git-compat-util.h"
#include "compat/terminal.h"
#include "sigchain.h"
#include "strbuf.h"
#include "run-command.h"
#include "string-list.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);
}
#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;
argv_array_push(&cp.args, "stty");
for (i = 0; i < stty_restore.nr; i++)
argv_array_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;
argv_array_push(&cp.args, "stty");
if (bits & ENABLE_LINE_INPUT) {
string_list_append(&stty_restore, "icanon");
argv_array_push(&cp.args, "-icanon");
}
if (bits & ENABLE_ECHO_INPUT) {
string_list_append(&stty_restore, "echo");
argv_array_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");
argv_array_push(&cp.args, "ignbrk");
argv_array_push(&cp.args, "intr");
argv_array_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);
}
#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;
}
#else
char *git_terminal_prompt(const char *prompt, int echo)
{
return getpass(prompt);
}
#endif