richw@ada-uts.UUCP (08/28/85)
I'm interested in coming up with an include file, say "handy.h",
which declares a lot of commonly useful "stuff". A lot of discussion
(an AWFUL lot) has been going on about Boolean typedefs/defines --
that's the sort of thing I'm looking for:
typedef enum { false, true } bool;
Other plausible candidates for this "second stdio.h" might be:
typedef char *string;
#define FORMFEED '\014' /* ASCII form feed */
Any other suggestions would be appreciated.
-- Rich Wagnerbc@cyb-eng.UUCP (Bill Crews) (08/30/85)
> > I'm interested in coming up with an include file, say "handy.h", > > -- Rich Wagner If people, when choosing names for functions, variables, files, etc, would think at least briefly about what name would be the most meaningful to an uninitiated reader, we readers would have a much easier time. I would suggest you come up with names like types.h or ctlchars.h or whatever, segregate them functionally and name them appropriately. -- / \ Bill Crews ( bc ) Cyb Systems, Inc \__/ Austin, Texas [ gatech | ihnp4 | nbires | seismo | ucbvax ] ! ut-sally ! cyb-eng ! bc
meister@linus.UUCP (Phillip W. Servita) (09/02/85)
> >I'm interested in coming up with an include file, say "handy.h", >which declares a lot of commonly useful "stuff". A lot of discussion > . > . > . >Any other suggestions would be appreciated. > >-- Rich Wagner my personal favorite: #define EVER ;; then you can say: for(EVER) { stuff; } -the venn buddhist
richw@ada-uts.UUCP (09/03/85)
>> I'm interested in coming up with an include file, say "handy.h", >> -- Rich Wagner > If people, when choosing names for functions, variables, files, etc, would > think at least briefly about what name would be the most meaningful to an > uninitiated reader, we readers would have a much easier time. I would > suggest you come up with names like types.h or ctlchars.h or whatever, > segregate them functionally and name them appropriately. > -- Bill Crews "segregate them functionally" -- I'm impressed :-) Now that you mention it, you've got a point. I originally didn't expect as many responses as I've gotten, so it will make sense to create several files (can you say ``modularity''?). Now, can we get back to the original question? Thanks to the replies I've gotten via e-mail -- a (personally edited; sorry) listing of ``good stuff'' will be posted soon... -- Rich
mike@whuxl.UUCP (BALDWIN) (09/03/85)
>I'm interested in coming up with an include file, say "handy.h", >which declares a lot of commonly useful "stuff". These can be "handy": #define NELEM(arr) (sizeof (arr) / sizeof *(arr)) #define LAST(arr) ((arr) + NELEM(arr)) e.g., struct vegetable potato[] = { "burbank", 0.34, "new", 3.44, "hot", 0.12, }; then struct vegetable *pp; for (pp = potato; pp < LAST(potato); pp++) or int i; for (i = 0; i < NELEM(potato); i++) I also like the usual string stuff: #define EQUAL(a,b) !strcmp(a,b) #define EQUALN(a,b,n) !strncmp(a,b,n) #define PREFIX(a,b) !strncmp(a,b,strlen(a)) #define COPY(a,b) strncpy(a,b,sizeof a) -- Michael Baldwin AT&T Bell Labs {at&t}!whuxl!mike
gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (09/03/85)
> #define EVER ;; > > then you can say: > > for(EVER) { > stuff; > } I think this illustrates one of the potential problems with hiding the actual language underneath definitions. If the loop REALLY continues "for ever", then it is probably not a good algorithm. Possibly #define repeatedly for ( ; ; ) would be a better fit to English. But (unlike the Boolean data type) the extra effort of becoming familiar with this usage does not seem to be adequately repaid in clearer code. (Of course that's a judgement call..)
lwall@sdcrdcf.UUCP (Larry Wall) (09/04/85)
Here's a chunk of code straight out of rn:
/* some handy defs */
#define bool char
#define TRUE (1)
#define FALSE (0)
#define Null(t) ((t)0)
#define Nullch Null(char *)
#define Nullfp Null(FILE *)
#define Ctl(ch) (ch & 037)
#define strNE(s1,s2) (strcmp(s1,s2))
#define strEQ(s1,s2) (!strcmp(s1,s2))
#define strnNE(s1,s2,l) (strncmp(s1,s2,l))
#define strnEQ(s1,s2,l) (!strncmp(s1,s2,l))
Larry Wall
{allegra,burdvax,cbosgd,hplabs,ihnp4,sdcsvax}!sdcrdcf!lwalldave@andromeda.UUCP (Dave Bloom) (09/04/85)
> >I'm interested in coming up with an include file, say "handy.h", >which declares a lot of commonly useful "stuff". A lot of discussion > . > . > . >Any other suggestions would be appreciated. > >-- Rich Wagner One of the most useful #defines I use religiously is for those times when you want to loop indefinately. Rather than say 'for(;;)', I say: #define loop for(;;) Then I can say things like: loop { etc. etc. etc. etc. etc. etc. } which seems much more to the point- Loop without condition.... -- ------------------------------------------------------------------------------- allegra\ Dave Bloom harvard \ pyramid\ seismo \ pyrnj >!andromeda!dave HOME: (201) 868-1764 ut-sally >!topaz/ WORK: (201) 648-5083 sri-iu / ihnp4!packard / "You're never alone with a schizophrenic...."
msb@lsuc.UUCP (Mark Brader) (09/05/85)
Michael Baldwin (whuxl!mike) suggests, among others: > #define NELEM(arr) (sizeof (arr) / sizeof *(arr)) > #define LAST(arr) ((arr) + NELEM(arr)) > for (pp = potato; pp < LAST(potato); pp++) and > #define COPY(a,b) strncpy(a,b,sizeof a) These are dangerous. LAST is misnamed, because it points to the space after the last element. If used, it should be called something like AFTERLAST. And with COPY, there is a temptation to call it with arguments of the wrong type. Can't you just see somebody writing fun(s) char s[]; { char temp[PLENTY_BIG]; ... COPY (s, temp); /* WRONG */ } and wondering why only the first few bytes were copied? Mark Brader
rbp@investor.UUCP (Bob Peirce) (09/06/85)
> my personal favorite: > > #define EVER ;; > > then you can say: > > for(EVER) { > stuff; > } Why not just #define FOREVER for(;;) Then you can say FOREVER{ stuff; } I actually have that in my "local.h" file, yet I persist in using "for(;;)!
wohletz@unrvax.UUCP (Greg Wohletz) (09/08/85)
In article <29@andromeda.UUCP> dave@andromeda.UUCP (Dave Bloom) writes: > > > > >I'm interested in coming up with an include file, say "handy.h", > >which declares a lot of commonly useful "stuff". A lot of discussion > > . > > . > > . > >Any other suggestions would be appreciated. > > > >-- Rich Wagner > >One of the most useful #defines I use religiously is for those times when you >want to loop indefinately. Rather than say 'for(;;)', I say: > >#define loop for(;;) > >Then I can say things like: > > loop { > etc. etc. etc. > etc. etc. etc. > } > >which seems much more to the point- Loop without condition.... >-- >------------------------------------------------------------------------------- Stuff like this really stinks! Try looking at the code for `sh' and you will understand... --Greg CSNet: greg%unlv@CSNet-Relay UUCP: {seismo , ucbvax!menlo70}!unr70!unrvax!unlv44!greg
mike@whuxl.UUCP (BALDWIN) (09/09/85)
> > #define NELEM(arr) (sizeof (arr) / sizeof *(arr)) > > #define LAST(arr) ((arr) + NELEM(arr)) > > #define COPY(a,b) strncpy(a,b,sizeof a) > > These are dangerous. LAST is misnamed, because it points to the > space after the last element. If used, it should be called > something like AFTERLAST. Yeh, you're right. LAST is too generic sounding. Reminds me of curses(3C), with move() and erase(), which conflict with routines of the same name in plot(3X)! But I still say the functions they perform are easier to read (with suitable names) than the corresponding x+y/z... > And with COPY, there is a temptation to call it with arguments of the > wrong type. Can't you just see somebody writing > > fun(s) > char s[]; > { > char temp[PLENTY_BIG]; > ... > COPY (s, temp); /* WRONG */ > } I don't know what to call this one. But I still think it's useful. It's not a general-purpose string copy macro; it's just useful when you want to copy a string to a safe place without scrogging the safe place. Hmm, maybe STRBUFSAVE? Oh hell, mebbe I'll just use strncpy! > Mark Brader Hey! *My* initials are MSB! Wild. -- Michael Scott Baldwin AT&T Bell Labs {at&t}!whuxl!mike
bet@ecsvax.UUCP (Bennett E. Todd III) (09/10/85)
I like the following:
#define ISPREFIX(s1, s2) !strncmp(s1, s2, strlen(s1))
It isn't clean, it isn't efficient, but it makes
if (ISPREFIX("command1", cmdbuff)) {
...
} else if (ISPREFIX("command2", cmdbuff)) {
...
reasonably clean. It refers to s1 twice, and it isn't fully
parenthesized, but it works for this limited application.
Now, somebody want to post a version of the notorious bit-table macros?
God, I wish spell(1) weren't proprietary, those are REALLY cute!
-Bennett
--
"Hypocrisy is the vasoline of social intercourse." (Who said that?)
Bennett Todd -- Duke Computation Center, Durham, NC 27706-7756; (919) 684-3695
UUCP: ...{decvax,seismo,philabs,ihnp4,akgua}!mcnc!ecsvax!duccpc!betfrascado@umn-cs.UUCP (Gregory Frascadore) (09/12/85)
>I'm interested in coming up with an include file, say "handy.h", >which declares a lot of commonly useful "stuff". A lot of discussion >Any other suggestions would be appreciated. >-- Rich Wagner One of my favorites is: #define repeat do #define until( expr) while( !(expr)) I prefer repeat-until loops over do-while's (my pascal heritage is showing :-) -- ------- Gregory Frascadore Computer Science Department University of Minnesota ...ihnp4!stolaf!umn-cs!frascado
carl@bdaemon.UUCP (carl) (09/14/85)
> > >> I'm interested in coming up with an include file, say "handy.h", > >> -- Rich Wagner > Without question one of the best "handy.h" files can be found in Tom Plum's book "Learning to Program in C" where it is called "local.h". While one may argue about some of the definitions used by Plum, it does illustrate what a "universally" useful include file might contain. Carl Brandauer daemon associates, Inc. 1760 Sunset Blvd. Boulder, CO 80302 303-442-1731 {allegra|amd|attunix|cbosgd|ucbvax}!nbires!bdaemon!carl