mirror of
https://github.com/RevCurtisP/C02.git
synced 2024-11-22 01:31:33 +00:00
140 lines
6.0 KiB
Plaintext
140 lines
6.0 KiB
Plaintext
File System Input/Output Functions for C02 Programs
|
|
|
|
This library contains functions for file handling. These functions
|
|
are included here instead of in stdio.h because not all 6502 systems
|
|
support file based input/output. Functions that are not part of the
|
|
standard C libraries begin with the letters "fs".
|
|
|
|
At the beginning of the program use the directives
|
|
|
|
#include <stdio.h02>
|
|
#include <file.h02>
|
|
|
|
The following functions are defined:
|
|
|
|
fsinit(); Initialize file system.
|
|
|
|
This function should be called before calling
|
|
before any other file functions.
|
|
|
|
Note: Closes any open files and initializes
|
|
the library's internal file table.
|
|
|
|
f = fsptr(); Find an available file pointer.
|
|
|
|
Returns 0 if no more file pointers are available.
|
|
|
|
Note: This is called by the fopen() function, which
|
|
does the actual file allocation and is of limited
|
|
use in application programming.
|
|
|
|
r = fschk(f); Check to see if f is a valid file pointer.
|
|
|
|
Returns 0 if valid, otherwise 255.
|
|
|
|
Note: Called by the fclose(), feof(), fgetc(),
|
|
fgets(), fputc(), fputs(), fread(), and fwrite()
|
|
functions.
|
|
|
|
r = fstat(f); Get status of file table entry or last file error.
|
|
|
|
If f is 0, returns a system dependent value
|
|
corresponding to the last filesystem I/O error.
|
|
|
|
If f is a potentially valid file pointer. returns a
|
|
value representing the state of the corresponding
|
|
entry in the file table. If the file table entry is
|
|
unused, then a 0 is returned. Otherwise, a system
|
|
dependent system dependent value is returned.
|
|
|
|
If f does not point to a valid file table entry,
|
|
then 255 is returned.
|
|
|
|
Note: On CBM machines, fstat(0) returns the result
|
|
of READST directly after the last error. Valid file
|
|
pointer values are between 1 and FOMAX, inclusive
|
|
and return a value with bits 0 through 3 containing
|
|
the Kernal device number, and bit 7 set if an End of
|
|
File or other error was encountered.
|
|
|
|
f = fopen(d, &n); Open file specified from null-terminated string n
|
|
on device d, returning a pointer to the file.
|
|
|
|
Return 0 if the file could not be opened.
|
|
|
|
Note: On CBM machines, d is the device number and
|
|
f is a logical file nunber as used in a Basic Open
|
|
statement. Up to 7 files may be opened at a time.
|
|
|
|
r = fclose(f); Close file pointed to by f, returning 0 if
|
|
successful or 255 if there was an error.
|
|
|
|
Note: Returns 255 if f is not a valid file pointer.
|
|
|
|
c = fgetc(f); Read character from file opened to by filepointer f.
|
|
|
|
Returns character read from file.
|
|
|
|
Note: Returns 255 if f is not a valid file pointer.
|
|
|
|
Returns a system dependent garbage character if end
|
|
of file has been reached or any other I/O error. Use
|
|
feof(f) and fstat(0) to check for these conditions.
|
|
|
|
fputc(f, c); Write character c to file opened to filepointer f.
|
|
|
|
Use feof(f) and fstat(0) to check for errors after
|
|
write.
|
|
|
|
-----------------------------------------------------------------
|
|
|
|
|
|
r = getstr(&s); Reads a maximum of 128 characters from keyboard
|
|
until the Return/Enter key is pressed, storing the
|
|
entered characters as null-terminated string s.
|
|
|
|
Allows corrections using Backspace/Delete.
|
|
|
|
Pressing the Escape/Abort key terminates entry,
|
|
leaving the string in an undefined state.
|
|
|
|
Returns number of characters entered, or 255
|
|
if entry was aborted.
|
|
|
|
Note: Calls getchr() in a loop and uses constants
|
|
DELKEY, RTNKEY, and ESCKEY from the system library.
|
|
|
|
|
|
r = putstr(&s): Writes up to 128 characters of null-terminated
|
|
string s to the screen and advances the cursor to
|
|
the beginning of the next line.
|
|
|
|
Returns number of characters printed.
|
|
|
|
Note: Calls outstr(&s) followed by newlin().
|
|
|
|
Note: This library expects the following functions to be defined:
|
|
|
|
setdst(&s); Set destination string pointer
|
|
setsrc(&s); Set source string pointer and initialize index
|
|
|
|
along with the zero page variable pairs
|
|
|
|
dstlo,dsthi: Destination string pointer
|
|
srclo,srchi: Source string pointer
|
|
|
|
the static array
|
|
|
|
ftbl[FOMAX]
|
|
|
|
and the assembler constant
|
|
|
|
FOMAX The maximum number of files that can be opened
|
|
at one time.
|
|
|
|
as well as the data structure
|
|
|
|
FTBL A system dependent table of bytes containing data
|
|
related to files opened by the fopen() function.
|
|
See function fstat() for more information.
|