root/compat/terminal.c

DEFINITIONS

1. restore_term_on_signal
2. restore_term
3. disable_echo
4. restore_term
5. disable_echo
6. git_terminal_prompt
7. git_terminal_prompt

#include "git-compat-util.h"
#include "compat/terminal.h"
#include "sigchain.h"
#include "strbuf.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_echo(void)
{
        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 &= ~ECHO;
        if (!tcsetattr(term_fd, TCSAFLUSH, &t))
                return 0;

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

#elif defined(GIT_WINDOWS_NATIVE)

#define INPUT_PATH "CONIN$"
#define OUTPUT_PATH "CONOUT$"
#define FORCE_TEXT "t"

static HANDLE hconin = INVALID_HANDLE_VALUE;
static DWORD cmode;

static void restore_term(void)
{
        if (hconin == INVALID_HANDLE_VALUE)
                return;

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

static int disable_echo(void)
{
        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 & (~ENABLE_ECHO_INPUT))) {
                CloseHandle(hconin);
                hconin = INVALID_HANDLE_VALUE;
                return -1;
        }

        return 0;
}

#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(&buf, input_fh, '\n');
        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