Example: fread
The following example, for Windows platforms, opens a file, reads the contents into a buffer using fread, and then closes the file.
To run the example, copy the file readme.txt from the installation's dat directory to the c drive, or copy another file and change the value of filename.
#include <stdio.h> int count, total = 0; char buffer[1000]; FILE* file_stream; char * filename = "c:\\readme.txt"; if ((file_stream = fopen(filename, "r")) == NULL ) { lr_error_message ("Cannot open %s", filename); return -1; }
// Read until end of file
while (!feof(file_stream)) {
// Read 1000 bytes while maintaining a running count
count = fread(buffer, sizeof(char), 1000, file_stream); lr_output_message ("%3d bytes read", count);
// Check for file I/O errors if (ferror(file_stream)) { lr_output_message ("Error reading file %s", filename); break; }
// Add up actual bytes read total += count; }
// Display final total
lr_output_message ("Total number of bytes read = %d", total );
// Close the file stream
if (fclose(file_stream)) lr_error_message ("Error closing file %s", filename);
Example: Output:
Action.c(19): 1000 bytes read
Action.c(19): 1000 bytes read
...
Action.c(19): 1000 bytes read
Action.c(20): 977 read
Action.c(34): Total number of bytes read = 69977