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ferror [2017/07/06 03:16] (current) |
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+ | ======Synopsis:====== | ||
+ | $[[ferror]](<<file descriptor>>) | ||
+ | |||
+ | ======Technical:====== | ||
+ | This function returns non-zero if an error has occurred on the | ||
+ | //file descriptor// since the last [[read]], because the [[read]] | ||
+ | and [[readb]] functions clear the //file descriptor//s error code. | ||
+ | |||
+ | When the [[read]] or [[readb]] function return the empty string, that | ||
+ | is caused either by an error, an eof, or a blank line. This function | ||
+ | will tell you if it was an error. The [[eof]] function will tell you | ||
+ | if it was an end of file. | ||
+ | |||
+ | The //file descriptor// must have been a value previously returned by | ||
+ | the [[open]] function. | ||
+ | |||
+ | ======Returns:====== | ||
+ | |-1 |Error: //file descriptor// was not previously returned by [[open]]| | ||
+ | | 0 |no error has occurred since the last [[read]]| | ||
+ | | 1 |an error has occurred since the last [[read]]| |