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Diffstat (limited to 'lib/isatty.c')
| -rw-r--r-- | lib/isatty.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/lib/isatty.c b/lib/isatty.c new file mode 100644 index 0000000..6cdc0fb --- /dev/null +++ b/lib/isatty.c @@ -0,0 +1,170 @@ +/* isatty() replacement. + Copyright (C) 2012-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include <unistd.h> + +/* This replacement is enabled on native Windows. */ + +#include <errno.h> +#include <string.h> + +/* Get declarations of the Win32 API functions. */ +#define WIN32_LEAN_AND_MEAN +#include <windows.h> + +#if HAVE_MSVC_INVALID_PARAMETER_HANDLER +# include "msvc-inval.h" +#endif + +/* Get _get_osfhandle(). */ +#if GNULIB_MSVC_NOTHROW +# include "msvc-nothrow.h" +#else +# include <io.h> +#endif + +/* Avoid warnings from gcc -Wcast-function-type. */ +#define GetProcAddress \ + (void *) GetProcAddress + +/* GetNamedPipeClientProcessId was introduced only in Windows Vista. */ +typedef BOOL (WINAPI * GetNamedPipeClientProcessIdFuncType) (HANDLE hPipe, + PULONG pClientProcessId); +static GetNamedPipeClientProcessIdFuncType GetNamedPipeClientProcessIdFunc = NULL; +/* QueryFullProcessImageName was introduced only in Windows Vista. */ +typedef BOOL (WINAPI * QueryFullProcessImageNameFuncType) (HANDLE hProcess, + DWORD dwFlags, + LPSTR lpExeName, + PDWORD pdwSize); +static QueryFullProcessImageNameFuncType QueryFullProcessImageNameFunc = NULL; +static BOOL initialized = FALSE; + +static void +initialize (void) +{ + HMODULE kernel32 = LoadLibrary ("kernel32.dll"); + if (kernel32 != NULL) + { + GetNamedPipeClientProcessIdFunc = + (GetNamedPipeClientProcessIdFuncType) GetProcAddress (kernel32, "GetNamedPipeClientProcessId"); + QueryFullProcessImageNameFunc = + (QueryFullProcessImageNameFuncType) GetProcAddress (kernel32, "QueryFullProcessImageNameA"); + } + initialized = TRUE; +} + +static BOOL IsConsoleHandle (HANDLE h) +{ + DWORD mode; + /* GetConsoleMode + <https://docs.microsoft.com/en-us/windows/console/getconsolemode> */ + return GetConsoleMode (h, &mode) != 0; +} + +static BOOL IsCygwinConsoleHandle (HANDLE h) +{ + /* A handle to a Cygwin console is in fact a named pipe whose client process + and server process is <CYGWIN_INSTALL_DIR>\bin\mintty.exe. */ + BOOL result = FALSE; + ULONG processId; + + if (!initialized) + initialize (); + + /* GetNamedPipeClientProcessId + <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getnamedpipeclientprocessid> + It requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher. */ + if (GetNamedPipeClientProcessIdFunc && QueryFullProcessImageNameFunc + && GetNamedPipeClientProcessIdFunc (h, &processId)) + { + /* OpenProcess + <https://docs.microsoft.com/en-us/windows/desktop/api/processthreadsapi/nf-processthreadsapi-openprocess> */ + HANDLE processHandle = + OpenProcess (PROCESS_QUERY_LIMITED_INFORMATION, FALSE, processId); + if (processHandle != NULL) + { + char buf[1024]; + DWORD bufsize = sizeof (buf); + /* The file name can be determined through + GetProcessImageFileName + <https://docs.microsoft.com/en-us/windows/desktop/api/psapi/nf-psapi-getprocessimagefilenamea> + or + QueryFullProcessImageName + <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-queryfullprocessimagenamea> + The former returns a file name in non-standard notation (it starts + with '\Device\') and may require linking with psapi.dll. + The latter is better, but requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA + or higher. */ + if (QueryFullProcessImageNameFunc (processHandle, 0, buf, &bufsize)) + { + if (strlen (buf) >= 11 + && strcmp (buf + strlen (buf) - 11, "\\mintty.exe") == 0) + result = TRUE; + } + CloseHandle (processHandle); + } + } + return result; +} + +#if HAVE_MSVC_INVALID_PARAMETER_HANDLER +static int +_isatty_nothrow (int fd) +{ + int result; + + TRY_MSVC_INVAL + { + result = _isatty (fd); + } + CATCH_MSVC_INVAL + { + result = 0; + } + DONE_MSVC_INVAL; + + return result; +} +#else +# define _isatty_nothrow _isatty +#endif + +/* Determine whether FD refers to a console device. Return 1 if yes. + Return 0 and set errno if no. (ptsname_r relies on the errno value.) */ +int +isatty (int fd) +{ + HANDLE h = (HANDLE) _get_osfhandle (fd); + if (h == INVALID_HANDLE_VALUE) + { + errno = EBADF; + return 0; + } + /* _isatty (fd) tests whether GetFileType of the handle is FILE_TYPE_CHAR. + But it does not set errno when it returns 0. */ + if (_isatty_nothrow (fd)) + { + if (IsConsoleHandle (h)) + return 1; + } + if (IsCygwinConsoleHandle (h)) + return 1; + errno = ENOTTY; + return 0; +} |