Dev Stack Source

Defined in header <stdio.h> void perror ( const char * s ) ; Prints a textual description of the error code currently stored in the system variable errno to stderr . The description is formed by concatenating the following components: the contents of the null-terminated byte string pointed to by s , followed by ": " (unless s is a null pointer or the character pointed to by s is the null character) implementation-defined error message string describing the error code stored in errno , followed by '\n' . The error message string is identical to the result of strerror ( errno ) . Parameters s - pointer to a null-terminated string with explanatory message Return value (none). Example # include <stdio.h> int main ( void ) { FILE * f = fopen ( "non_existent" , "r" ) ; if ( f == NULL ) { perror ( "fopen() failed" ) ; } else { fclose...

Defined in header <stdio.h> size_t fread ( void * buffer , size_t size , size_t count , FILE * stream ) ; (until C99) size_t fread ( void * restrict buffer , size_t size , size_t count , FILE * restrict stream ) ; (since C99) Reads up to count objects into the array buffer from the given input stream stream as if by calling fgetc size times for each object, and storing the results, in the order obtained, into the successive positions of buffer , which is reinterpreted as an array of unsigned char . The file position indicator for the stream is advanced by the number of characters read. If an error occurs, the resulting value of the file position indicator for the stream is indeterminate. If a partial element is read, its value is indeterminate. Parameters buffer - pointer to the array where the read objects are stored size - size of each object in bytes co...