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()
{
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)