Page 133 - DCAP408_WEB_PROGRAMMING

Unit 8: File I/O

exit(1); Notes
}
The stream may be access via fprintf or fscanf, and should be subsequently closed with fclose. (In
windows programs, HaltCL should be used instead of exit.)
fclose
fclose closes a stream previously opened with fopen. (Declared in stdio.h.)

int fclose(FILE *stream);
A simple use of fclose might look like
FILE *my_file;
/* .. */
my_file = fopen(“datafile.txt”, “r”);
/* .. */
fclose(my_file);
fprintf
fprintf is the analogue of printf for use with arbitrary streams. (Declared
in stdio.h.)
int fprintf(FILE *stream, const char *format, ... );

Example: To open a disk-file and write some text to it:
FILE *my_file;
int i;
/* .. */
my_file=fopen(“datafile.txt”,”w”);
fprintf(my_file, “i=%d”, i);
/* .. */
fclose(my_file);
The meaning of the second and subsequent arguments to fprintf are described in printf.
fscanf
fscanf is the analogue of scanf for use with arbitrary streams. (Declared
in stdio.h.)
int fscanf(FILE *stream, const char *format, ... );

Example: To open a disk-file and read some text from it:
FILE *my_file;
int i;
/* .. */
my_file=fopen(“datafile.txt”,”r”);
fscanf(my_file, “%d”, &i); /* read an integer from the file into i */
/* .. */
fclose(my_file);

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