liveMedia/InputFile.cpp

/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library 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 Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2020 Live Networks, Inc.  All rights reserved.
// Common routines for opening/closing named input files
// Implementation

#include "InputFile.hh"
#include <string.h>

FILE* OpenInputFile(UsageEnvironment& env, char const* fileName) {
  FILE* fid;

  // Check for a special case file name: "stdin"
  if (strcmp(fileName, "stdin") == 0) {
    fid = stdin;
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
    _setmode(_fileno(stdin), _O_BINARY); // convert to binary mode
#endif
  } else {
    fid = fopen(fileName, "rb");
    if (fid == NULL) {
      env.setResultMsg("unable to open file \"",fileName, "\"");
    }
  }

  return fid;
}

void CloseInputFile(FILE* fid) {
  // Don't close 'stdin', in case we want to use it again later.
  if (fid != NULL && fid != stdin) fclose(fid);
}

u_int64_t GetFileSize(char const* fileName, FILE* fid) {
  u_int64_t fileSize = 0; // by default

  if (fid != stdin) {
#if !defined(_WIN32_WCE)
    if (fileName == NULL) {
#endif
      if (fid != NULL && SeekFile64(fid, 0, SEEK_END) >= 0) {
	fileSize = (u_int64_t)TellFile64(fid);
	if (fileSize == (u_int64_t)-1) fileSize = 0; // TellFile64() failed
	SeekFile64(fid, 0, SEEK_SET);
      }
#if !defined(_WIN32_WCE)
    } else {
      struct stat sb;
      if (stat(fileName, &sb) == 0) {
	fileSize = sb.st_size;
      }
    }
#endif
  }

  return fileSize;
}

int64_t SeekFile64(FILE *fid, int64_t offset, int whence) {
  if (fid == NULL) return -1;

  clearerr(fid);
  fflush(fid);
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
  return _lseeki64(_fileno(fid), offset, whence) == (int64_t)-1 ? -1 : 0;
#else
#if defined(_WIN32_WCE)
  return fseek(fid, (long)(offset), whence);
#else
  return fseeko(fid, (off_t)(offset), whence);
#endif
#endif
}

int64_t TellFile64(FILE *fid) {
  if (fid == NULL) return -1;

  clearerr(fid);
  fflush(fid);
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
  return _telli64(_fileno(fid));
#else
#if defined(_WIN32_WCE)
  return ftell(fid);
#else
  return ftello(fid);
#endif
#endif
}

Boolean FileIsSeekable(FILE *fid) {
  if (SeekFile64(fid, 1, SEEK_CUR) < 0) {
    return False;
  }

  SeekFile64(fid, -1, SEEK_CUR); // seek back to where we were
  return True;
}