c question: *printf'ing arrays

[Alfred Perlstein]

Hey Alex,

People frown on macros, but this could be a good one:

#define SPRINT(f, fmt) \
	do {\
		for (_i = 0; _i < sizeof(f)/sizeof(f[0]); i++) \
			printf(fmt, f[i]); \
	}while(0)

:D

This should allow you to point to any _array_ and print each
element of it using format "fmt".

Example:
SPRINT(Header->game_title, "%c");



-Alfred
	

* Alexander Best <alexbestms at math.uni-muenster.de> [090630 15:06] wrote:
> thanks for all the help. i decided to take the pill and coded all the fprintfs
> by hand. here's the result. usually i'd stick to a higher level languag, but i
> need C's inline assembly support:
> 
>     struct Header
>     {
>         u_int8_t rom_entry[4];
>         u_int8_t nintendo_logo[156];
>         u_char game_title[12];
>         u_char game_code[4];
>         u_char maker_code[2];
>         u_int8_t fixed_val;
>         u_int8_t unit_code;
>         u_int8_t device_type;
>         u_int8_t reserved_area1[7];
>         u_int8_t software_version;
>         u_int8_t complement_check;
>         u_int8_t reserved_area2;
>         u_int8_t ram_entry[4];
>         u_int8_t boot_mode;
>         u_int8_t slave_id;
>         u_int8_t unused_area[26];
>         u_int8_t joybus_entry[4];
>     };
> 
>     struct Header * hdr = rom;
>     int i;
> 
>     fprintf(stderr, "ROM Entry: 0x");
>     for (i=0; i < 4; i++) fprintf(stderr, "%x", hdr->rom_entry[i]);
>     fprintf(stderr, "\nNintendo Logo: 0x");
>     for (i=0; i < sizeof(hdr->nintendo_logo); i++) fprintf(stderr, "%x",
>     hdr->nintendo_logo[i]);
>     fprintf(stderr, "\nGame Title: %s",  hdr->game_title);
>     fprintf(stderr, "\nGame Code: %s",  hdr->game_code);
>     fprintf(stderr, "\nMaker Code: %s",  hdr->maker_code);
>     fprintf(stderr, "\nFixed Value: 0x");
>     fprintf(stderr, "%x", hdr->fixed_val);
>     fprintf(stderr, "\nUnit Code: 0x");
>     fprintf(stderr, "%x", hdr->unit_code);
>     fprintf(stderr, "\nDevice Type: 0x");
>     fprintf(stderr, "%x", hdr->device_type);
>     fprintf(stderr, "\nReserved Area: 0x");
>     for (i=0; i < sizeof(hdr->reserved_area1); i++) fprintf(stderr, "%x",
>     hdr->reserved_area1[i]);
>     fprintf(stderr, "\nSoftware Version: 0x");
>     fprintf(stderr, "%x", hdr->software_version);
>     fprintf(stderr, "\nComplement Check: 0x");
>     fprintf(stderr, "%x", hdr->complement_check);
>     fprintf(stderr, "\nReserved Area: 0x");
>     fprintf(stderr, "%x", hdr->reserved_area2);
>     fprintf(stderr, "\nRAM Entry Point: 0x");
>     for (i=0; i < sizeof(hdr->ram_entry); i++) fprintf(stderr, "%x",
>     hdr->ram_entry[i]);
>     fprintf(stderr, "\nBoot Mode: 0x");
>     fprintf(stderr, "%x", hdr->boot_mode);
>     fprintf(stderr, "\nSlave ID: 0x");
>     fprintf(stderr, "%x", hdr->slave_id);
>     fprintf(stderr, "\nUnused Area: 0x");
>     for (i=0; i < sizeof(hdr->unused_area); i++) fprintf(stderr, "%x",
>     hdr->unused_area[i]);
>     fprintf(stderr, "\nJoybus Entry Point: 0x");
>     for (i=0; i < sizeof(hdr->joybus_entry); i++) fprintf(stderr, "%x",
>     hdr->joybus_entry[i]);
> 
> cheers.
> 
> Rick C. Petty schrieb am 2009-06-30:
> > On Tue, Jun 30, 2009 at 08:21:03PM +0200, Alexander Best wrote:
> > > thanks. now the output gets redirected using >. i'm quite new to
> > > programming
> > > under unix. sorry for the inconvenience.
> 
> > No problem; we all had to learn sometime.  But what I suggested
> > should
> > work for every platform that adheres to POSIX.  If you were using
> > fprintf/fwrite, then it would work on anything that's standard C.  As
> > for
> > redirection, windows command line allows the same type of
> > redirection.
> 
> > > so i guess there is no really easy way to output an inhomogeneous
> > > struct to
> > > stdout without using a loop to output each array contained in the
> > > struct.
> 
> > That's not something C would ever provide easily.  You may want to
> > use a
> > different high-level language.  However, I often use macros for
> > printing
> > pieces of structures, for example I used this to print out sizes of
> > kernel
> > structures:
> 
> > #define SIZE(astruct, member) \
> >         printf("%d\t\t.%s\n", sizeof(astruct.member), #member)
> 
> > #include <sys/ktrace.h>
> > ...
> >         struct ktr_header header;
> >         struct ktr_genio genio;
> 
> >         printf("%d\tktr_header:\n", sizeof(header));
> >         SIZE(header, ktr_len);
> >         SIZE(header, ktr_type);
> >         SIZE(header, ktr_pid);
> >         SIZE(header, ktr_comm);
> >         SIZE(header, ktr_time);
> >         SIZE(header, ktr_time.tv_sec);
> >         SIZE(header, ktr_time.tv_sec);
> >         SIZE(header, ktr_tid);
> 
> >         printf("\n%d\tktr_genio:\n", sizeof(genio));
> >         SIZE(genio, ktr_fd);
> >         SIZE(genio, ktr_rw);
> 
> > In your case, you could make a macro for each type.  Without an
> > example of
> > how you want the output to look, it's hard for us to show you code
> > that
> > will produce such output.
> 
> > -- Rick C. Petty
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-- 
- Alfred Perlstein
VMOA #5191, 03 vmax, 92 gs500, ch250 - FreeBSD