std::feof (3) - Linux Man Pages

std::feof: std::feof

NAME

std::feof - std::feof

Synopsis


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


Checks if the end of the given file stream has been reached.

Parameters


stream - the file stream to check

Return value


Nonzero value if the end of the stream has been reached, otherwise 0.

Notes


This function only reports the stream state as reported by the most recent I/O operation, it does not examine the associated data source. For example, if the most recent I/O was a std::fgetc, which returned the last byte of a file, std::feof returns zero. The next std::fgetc fails and changes the stream state to end-of-file. Only then std::feof returns non-zero.
In typical usage, input stream processing stops on any error; feof and std::ferror are then used to distinguish between different error conditions.

Example


// Run this code


  #include <cstdio>
  #include <cstdlib>


  int main()
  {
      FILE* fp = std::fopen("test.txt", "r");
      if(!fp) {
          std::perror("File opening failed");
          return EXIT_FAILURE;
      }


      int c; // note: int, not char, required to handle EOF
      while ((c = std::fgetc(fp)) != EOF) { // standard C I/O file reading loop
         std::putchar(c);
      }


      if (std::ferror(fp))
          std::puts("I/O error when reading");
      else if (std::feof(fp))
          std::puts("End of file reached successfully");


      std::fclose(fp);
  }

See also


         checks if end-of-file has been reached
eof (public member function of std::basic_ios<CharT,Traits>)
         clears errors
clearerr (function)
         displays a character string corresponding of the current error to stderr
perror (function)
         checks for a file error
ferror (function)