std::ferror

 

C++

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scanffscanfsscanf vscanfvfscanfvsscanf (C++11)(C++11)(C++11) printffprintfsprintfsnprintf (C++11) vprintfvfprintfvsprintfvsnprintf (C++11)	wscanffwscanfswscanf vwscanfvfwscanfvswscanf (C++11)(C++11)(C++11) wprintffwprintfswprintf vwprintfvfwprintfvswprintf
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clearerr
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ferror
perror
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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>
 
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");
}

See also

clearerr	clears errors (function)
feof	checks for the end-of-file (function)
perror	displays a character string corresponding of the current error to stderr (function)
C documentation for ferror