BDS C User's Guide Addenda
v1.44 Edition -- April, 1981
Leor Zolman
BD Software
33 Lothrop st.
Brighton, Massachussetts 02135
Actually, I managed to wipe out my only copy of the v1.44 update sheet
when my hard disk crashed a little while ago, but I'm re-typing it from the
hard copy just for placement into ar25:cpm;. Thus, the entries may be a bit
more terse than the originals, but I think the info will still get across.
Here are the bug fixes/enhancements for version 1.44:
1. (v1.43a only): the character sequence \\ at the END of a quoted string
caused the preprocessor to screw up comment handling. For example,
printf("This backslash would cause bit trouble: \\");
would have done it.
2. The "qsort" function didn't work when the total size of the data array
being sorted exceeded 32K bytes. This has been fixed by changing the
declarations of certain variables in the function from "int" to
"unsigned".
3. CC1, CC2 and CLINK may now be aborted in mid-execution by typing
control-C.
4. A new CLINK option, "-f", may be placed before a CRL filename to FORCE all
functions in that CRL file to be loaded immediately, regardless of whether
they have been referenced yet or not. The "-f" only affects one CRL file,
and the next file mentioned is again only scanned for needed functions
(unless "-f" is used again.)
5. The "rename" library function had a rather serious problem: whenever
executed, it would zero out the three bytes immediately following the end
of the "rename" function in memory, thus wiping out the first jump table
vector of the next function! This was fixed by increasing the "ds"
statement at the end of the rename function (in deff2.asm) from 49 to 53.
6. The "setfcb" function requires that the buffer allocated to hold the
resulting fcb is at least 36 bytes long (not just 32 or 33.)...this is
because "setfcb" zeros out the random-record fields for CP/M 2.x, whether
or not they are needed.
7. A character constant consisting of the double-quote character enclosed in
single quotes ('"'), caused CC1 to go haywire in the comment- stripping
phase.
8. Whenever the "type" information for a function definition was placed on a
line separate from the actual name of the function, the compiler would
"lose" one line number for error reporting, and all errors found past that
point in the file would be reported with an incorrect line number. For
example, the following text would have caused that problem:
char *
foo()
{
...
}
9. A new library function, "execv", has been added to the package (source is
in DEFF2.ASM). This function is like "execl", except that a variable
number of parameters is passed by placing them into an array and passing a
pointer to the array instead of the actual parameters. The format of the
"execv" function is:
execv(prog,argvp)
char *prog, **argvp;
where `prog' points to the name of the COM file to be executed, and
`argvp' is an `argv'-like pointer to an array of pointers to text
parameters. The final entry in the list must be a null pointer. As an
example, note that the "execl" call
Pre-v1.45 version of the package contained an "execv" that printed the
message "broken pipe" on the console and re-booted CP/M whenever "execv"
couldn't find the program is was supposed to execute; v1.45 contains an
"execv" that simply returns -1 (ERROR) when the program cannot be found.
10. Directed I/O and pipes, of sorts, are now available to BDS C programmers.
The files DIO.C and DIO.H make up a cute little directed I/O package,
allowing for directed input, directed output and pipes (a la Unix) on the
command line to programs compiled with this special I/O package. See the
comments in DIO.C for complete details. Note that the presence of this
package does NOT contradict certain comments made in the BDS C User's
Guide about kludging advanced Unix features under CP/M; those comments
were directed toward systems in which the I/O redirected/generalization is
forced upon the user, along with all the entailing overhead, when the
redirection isn't needed or wanted for many applications. The DIO package,
being written in C and separately compiled, lets YOU decide when you want
it and when you do not. If you don't want it, it takes up zero space; if
you do, it takes up a little room and yanks in all the buffered I/O, but
it DOES give you redirection and pipes!
11. a "standard error" buffered I/O stream number has been added to the list
of special devices recognized by the "putc" buffered output function (and
thus all the buffered output functions that use "putc"). An `iobuf' value
of 4 causes the character given to be written to the CP/M console output,
always, while an `iobuf' value of 1 causes the character to be written to
the standard output (which might be a file if the DIO package is in use.)
Note that the value of 4 was chosed instead of 2 (the Unix standard)
because 2 was already taken to mean the CP/M lst: device.
12. String constants may now contain zero bytes within them. Previous versions
have flagged lines such as
