std::ferror (3) - Linux Manuals

std::ferror: std::ferror

NAME

std::ferror - std::ferror

Synopsis

Defined in header <cstdio>
int ferror( std::FILE* stream );

Checks the given stream for errors.

Parameters

stream - the file stream to check

Return value

Nonzero value if the file stream has errors occurred, 0 otherwise

Example

// Run this code

  #include <cstdio>
  #include <cstdlib>
  #include <clocale>
  #include <cwchar>

  int main(void)
  {
      const char *fname = std::tmpnam(nullptr);
      std::FILE* f = std::fopen(fname, "wb");
      std::fputs("\xff\xff\n", f); // not a valid UTF-8 character sequence
      std::fclose(f);

      std::setlocale(LC_ALL, "en_US.utf8");
      f = std::fopen(fname, "rb");
      std::wint_t ch;
      while ((ch=std::fgetwc(f)) != WEOF) // attempt to read as UTF-8
            std::printf("%#x ", ch);

      if (std::feof(f))
          puts("EOF indicator set");
      if (std::ferror(f))
          puts("Error indicator set");
  }

Output:

  Error indicator set