feof
From cppreference.com
| Defined in header <stdio.h>
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| int feof( FILE *stream ); |
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Checks if the end of the given file stream has been reached.
Contents |
[edit] Parameters
| stream | - | the file stream to check |
[edit] Return value
nonzero value if the end of the stream has been reached, otherwise 0
[edit] 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 fgetc, which returned the last byte of a file, feof returns zero. The next fgetc fails and changes the stream state to end-of-file. Only then feof returns non-zero.
In typical usage, input stream processing stops on any error; feof and ferror are then used to distinguish between different error conditions.
[edit] Example
Run this code
#include <stdio.h> #include <stdlib.h> int main(void) { const char* fname = "/tmp/unique_name.txt"; // or tmpnam(NULL); int is_ok = EXIT_FAILURE; FILE* fp = fopen(fname, "w+"); if (!fp) { perror("File opening failed"); return is_ok; } fputs("Hello, world!\n", fp); rewind(fp); int c; // note: int, not char, required to handle EOF while ((c = fgetc(fp)) != EOF) // standard C I/O file reading loop putchar(c); if (ferror(fp)) puts("I/O error when reading"); else if (feof(fp)) { puts("End of file is reached successfully"); is_ok = EXIT_SUCCESS; } fclose(fp); remove(fname); return is_ok; }
Possible output:
Hello, world! End of file is reached successfully
[edit] References
- C11 standard (ISO/IEC 9899:2011):
- 7.21.10.2 The feof function (p: 339)
- C99 standard (ISO/IEC 9899:1999):
- 7.19.10.2 The feof function (p: 305)
- C89/C90 standard (ISO/IEC 9899:1990):
- 4.9.10.2 The feof function
[edit] See also
| clears errors (function) | |
| displays a character string corresponding of the current error to stderr (function) | |
| checks for a file error (function) | |
| C++ documentation for feof
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