diff options
Diffstat (limited to 'libc/stdio1/old_printf.c')
| -rw-r--r-- | libc/stdio1/old_printf.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/libc/stdio1/old_printf.c b/libc/stdio1/old_printf.c new file mode 100644 index 0000000..81d62ac --- /dev/null +++ b/libc/stdio1/old_printf.c @@ -0,0 +1,230 @@ +/* fprintf.c for limited Linux libc + Copyright (C) 1996 Joel N. Weber II <nemo@koa.iolani.honolulu.hi.us> + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +/* Thanks Alan for writing the hard routine for me :-) + * Alan said that this works "most of the time". Something tells me I'm making + * it even worse! */ +/* The basic idea here is to make fprintf the core routine. printf obviously + can just call fprintf with stdout followed by all of its arguments. + sprintf() works using the fake file &the_sprintf. It's marked as fully + buffered, so that it will only write(2) when &the_sprintf->bufpos == + &the_sprintf->bufend, which I doubt will happen since &the_sprintf->bufend + = 0. The trick is that sprintf must set &the_sprintf->bufstart = + &the_sprintf->bufpos = its first argument. Not as orthagonal (is that + the right word?) as glibc's facilities for non-files, but this isn't a + library for people who have unlimited RAM budgets. (not like the libc + I use on linux/i586 enjoys an unlimited RAM budget either; I only have + 8 MB + + I'm not sure what the "correct" way to pass the variable arguments + from one function to the next is. Rather than pass the arguments + themselves, I'm passing a pointer to them. However, the following + explaination from Alan is probably a polite way of saying it will not + work on a 386 anyway. + Joel Weber + + [ I've migrated all of this code over to the ELKS stdarg that I wrote. + The accepted way to do it is for the wrapper function to accept a + variable number of arguments, use stdarg to make an argument pointer, + and then pass the argument pointer on to the core function, as I've + done here. This should definitely work on a 386, as the arguments + are still passed in the stack, and stack order is maintained. -Nat ] + */ + +/* + * This is NOT stunningly portable, but works + * for pretty dumb non ANSI compilers and is + * tight. Adjust the sizes to taste. + * + * Illegal format strings will break it. Only the + * following simple subset is supported + * + * %x - hex + * %d - decimal + * %s - string + * %c - char + * + * And the h/l length specifiers for %d/%x + * + * Alan Cox. + */ + +#include <stdarg.h> +#include "stdio.h" + +/* 17 to make sure that there's room for the trailing newline. + I'm not really sure if this is ideal... */ +static char nstring[17]="0123456789ABCDEF"; + +static unsigned char * +__numout(long i, int base) +{ + static unsigned char out[16]; + int n; + int flg = 0; + unsigned long val; + + if (i<0 && base==10) + { + flg = 1; + i = -i; + } + val = i; + + for (n = 0; n < 15; n++) + out[n] = ' '; + out[15] = '\0'; + n = 14; + do{ + out[n] = nstring[val % base]; + n--; + val /= base; + } + while(val); + if(flg) out[n--] = '-'; + return &out[n+1]; +} + +static int +internal_fprintf(FILE * stream, __const char * fmt, va_list ap) +{ + register int c; + int count = 0; + int type, base; + + while(c=*fmt++) + { + if(c!='%') + { + putc(c, stream); + count++; + } + else + { + type=1; + do { c=*fmt++; } while( c=='.' || (c>='0' && c<='9')); + if( c == 0 ) break; + if(c=='h') + { + c=*fmt++; + type = 0; + } + else if(c=='l') + { + c=*fmt++; + type = 2; + } + + switch(c) + { + case 'x': + case 'o': + case 'd': + if (c=='x') base=16; + if (c=='o') base=8; + if (c=='d') base=10; + { + long val=0; + switch(type) + { + case 0: + val=va_arg(ap, short); + break; + case 1: + val=va_arg(ap, int); + break; + case 2: + val=va_arg(ap, long); + break; + } + fputs((__const char *)__numout(val,base),stream); + } + break; + case 's': + { + char *cp; + cp=va_arg(ap, char *); + while(*cp) + putc(*cp++, stream); + break; + } + case 'c': + putc(va_arg(ap, int), stream); + break; + default: + putc(c, stream); + } + } + } + return count; +} + + +int +fprintf(FILE * stream, __const char * fmt, ...) +{ + va_list ap; + int retval; + va_start(ap, fmt); + retval=internal_fprintf(stream, fmt, ap); + va_end(ap); + return(retval); +} + +int +printf(__const char * fmt, ...) +{ + va_list ap; + int retval; + va_start(ap, fmt); + retval=internal_fprintf(stdout, fmt, ap); + va_end(ap); + return(retval); +} + +/* This is a strange way of doing sprintf, but it should work */ +int sprintf(char * s, __const char * fmt, ...) +{ + static FILE the_sprintf = { + -1, + 0, + 0, + 0, + 0, + _IOFBF, + _MODE_WRITE, + 0, 0, + 0, 0}; + va_list ap; + int retval; + + va_start(ap, fmt); + the_sprintf.bufstart = the_sprintf.bufpos = (unsigned char *) s; + the_sprintf.fc_err = 0; + + retval = internal_fprintf(&the_sprintf, fmt, ap); + /* null-terminate the string */ + putc('\0', &the_sprintf); + + va_end(ap); + return retval; +} + + + + + |