FILE *fopen( const char *filename, const char *type )
- prototype in stdio.h - type is a combination of the following: Mode Description "r" read text/binary "w" write text/binary "a" append text/binary "+" allow update access "t" text file "b" binary file Read Write Append "rt" "wt" "at" (text) "rb" "wb" "ab" (binary) "r+" "w+" "a+" (update) "r+t" "w+t" "a+t" (update text) "r+b" "w+b" "a+b" (update binary) read - read only (unless "r+") write - create append - seek to end of file or create file - text mode input, will have CRs discarded - using any of the stdio functions results in a default allocation of 512 bytes for the I/O buffer and the inclusion of the standard memory allocation functions - returns stream or NULL on error