std::feof

 

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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()
{
    int is_ok = EXIT_FAILURE;
    FILE* fp = std::fopen("/tmp/test.txt", "w+");
    if(!fp) {
        std::perror("File opening failed");
        return is_ok;
    }
 
    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");
        is_ok = EXIT_SUCCESS;
    }
 
    std::fclose(fp);
    return is_ok;
}

Output:

End of file reached successfully

See also

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