ref: b0377e84cf31c48afed765c433abe7eebb4135a5
dir: /sys/src/libstdio/vfscanf.c/
/*
* pANS stdio -- vfscanf
*/
#include "iolib.h"
#include <ctype.h>
static int icvt_f(FILE *f, va_list *args, int store, int width, int type);
static int icvt_x(FILE *f, va_list *args, int store, int width, int type);
static int icvt_sq(FILE *f, va_list *args, int store, int width, int type);
static int icvt_c(FILE *f, va_list *args, int store, int width, int type);
static int icvt_d(FILE *f, va_list *args, int store, int width, int type);
static int icvt_i(FILE *f, va_list *args, int store, int width, int type);
static int icvt_n(FILE *f, va_list *args, int store, int width, int type);
static int icvt_o(FILE *f, va_list *args, int store, int width, int type);
static int icvt_p(FILE *f, va_list *args, int store, int width, int type);
static int icvt_s(FILE *f, va_list *args, int store, int width, int type);
static int icvt_u(FILE *f, va_list *args, int store, int width, int type);
static int (*icvt[])(FILE *, va_list *, int, int, int)={
0, 0, 0, 0, 0, 0, 0, 0, /* ^@ ^A ^B ^C ^D ^E ^F ^G */
0, 0, 0, 0, 0, 0, 0, 0, /* ^H ^I ^J ^K ^L ^M ^N ^O */
0, 0, 0, 0, 0, 0, 0, 0, /* ^P ^Q ^R ^S ^T ^U ^V ^W */
0, 0, 0, 0, 0, 0, 0, 0, /* ^X ^Y ^Z ^[ ^\ ^] ^^ ^_ */
0, 0, 0, 0, 0, 0, 0, 0, /* sp ! " # $ % & ' */
0, 0, 0, 0, 0, 0, 0, 0, /* ( ) * + , - . / */
0, 0, 0, 0, 0, 0, 0, 0, /* 0 1 2 3 4 5 6 7 */
0, 0, 0, 0, 0, 0, 0, 0, /* 8 9 : ; < = > ? */
0, 0, 0, 0, 0, icvt_f, 0, icvt_f, /* @ A B C D E F G */
0, 0, 0, 0, 0, 0, 0, 0, /* H I J K L M N O */
0, 0, 0, 0, 0, 0, 0, 0, /* P Q R S T U V W */
icvt_x, 0, 0, icvt_sq,0, 0, 0, 0, /* X Y Z [ \ ] ^ _ */
0, 0, 0, icvt_c, icvt_d, icvt_f, icvt_f, icvt_f, /* ` a b c d e f g */
0, icvt_i, 0, 0, 0, 0, icvt_n, icvt_o, /* h i j k l m n o */
icvt_p, 0, 0, icvt_s, 0, icvt_u, 0, 0, /* p q r s t u v w */
icvt_x, 0, 0, 0, 0, 0, 0, 0, /* x y z { | } ~ ^? */
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
#define ngetc(f) (nread++, getc(f))
#define nungetc(c, f) (--nread, ungetc((c), f))
#define wgetc(c, f, out) if(width--==0) goto out; (c)=ngetc(f)
#define wungetc(c, f) (++width, nungetc(c, f))
static int nread, ncvt;
static const char *fmtp;
int vfscanf(FILE *f, const char *s, va_list args){
int c, width, type, store;
nread=0;
ncvt=0;
fmtp=s;
for(;*fmtp;fmtp++) switch(*fmtp){
default:
if(isspace(*fmtp)){
do
c=ngetc(f);
while(isspace(c));
nungetc(c, f);
break;
}
NonSpecial:
c=ngetc(f);
if(c==EOF) return ncvt?ncvt:EOF;
if(c!=*fmtp){
nungetc(c, f);
return ncvt;
}
break;
case '%':
fmtp++;
if(*fmtp!='*') store=1;
else{
store=0;
fmtp++;
}
if('0'<=*fmtp && *fmtp<='9'){
width=0;
while('0'<=*fmtp && *fmtp<='9') width=width*10 + *fmtp++ - '0';
}
else
width=-1;
type=*fmtp=='h' || *fmtp=='l' || *fmtp=='L'?*fmtp++:'n';
if(!icvt[*fmtp]) goto NonSpecial;
if(!(*icvt[*fmtp])(f, &args, store, width, type))
return ncvt?ncvt:EOF;
if(*fmtp=='\0') break;
if(store) ncvt++;
}
return ncvt;
}
static int icvt_n(FILE *f, va_list *args, int store, int width, int type){
if(store){
--ncvt; /* this assignment doesn't count! */
switch(type){
case 'h': *va_arg(*args, short *)=nread; break;
case 'n': *va_arg(*args, int *)=nread; break;
case 'l':
case 'L': *va_arg(*args, long *)=nread; break;
}
}
return 1;
}
#define SIGNED 1
#define UNSIGNED 2
#define POINTER 3
/*
* Generic fixed-point conversion
* f is the input FILE *;
* args is the va_list * into which to store the number;
* store is a flag to enable storing;
* width is the maximum field width;
* type is 'h' 'l' or 'L', the scanf type modifier;
* unsgned is SIGNED, UNSIGNED or POINTER, giving part of the type to store in;
* base is the number base -- if 0, C number syntax is used.
*/
static int icvt_fixed(FILE *f, va_list *args,
int store, int width, int type, int unsgned, int base){
unsigned long int num=0;
int sign=1, ndig=0, dig;
int c;
do
c=ngetc(f);
while(isspace(c));
if(width--==0){
nungetc(c, f);
goto Done;
}
if(c=='+'){
wgetc(c, f, Done);
}
else if(c=='-'){
sign=-1;
wgetc(c, f, Done);
}
switch(base){
case 0:
if(c=='0'){
wgetc(c, f, Done);
if(c=='x' || c=='X'){
wgetc(c, f, Done);
base=16;
}
else{
ndig=1;
base=8;
}
}
else
base=10;
break;
case 16:
if(c=='0'){
wgetc(c, f, Done);
if(c=='x' || c=='X'){
wgetc(c, f, Done);
}
else ndig=1;
}
break;
}
while('0'<=c && c<='9' || 'a'<=c && c<='f' || 'A'<=c && c<='F'){
dig='0'<=c && c<='9'?c-'0':'a'<=c && c<='f'?c-'a'+10:c-'A'+10;
if(dig>=base) break;
ndig++;
num=num*base+dig;
wgetc(c, f, Done);
}
nungetc(c, f);
Done:
if(ndig==0) return 0;
if(store){
switch(unsgned){
case SIGNED:
switch(type){
case 'h': *va_arg(*args, short *)=num*sign; break;
case 'n': *va_arg(*args, int *)=num*sign; break;
case 'l':
case 'L': *va_arg(*args, long *)=num*sign; break;
}
break;
case UNSIGNED:
switch(type){
case 'h': *va_arg(*args, unsigned short *)=num*sign; break;
case 'n': *va_arg(*args, unsigned int *)=num*sign; break;
case 'l':
case 'L': *va_arg(*args, unsigned long *)=num*sign; break;
}
break;
case POINTER:
*va_arg(*args, void **)=(void *)(num*sign); break;
}
}
return 1;
}
static int icvt_d(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, SIGNED, 10);
}
static int icvt_x(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, UNSIGNED, 16);
}
static int icvt_o(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, UNSIGNED, 8);
}
static int icvt_i(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, SIGNED, 0);
}
static int icvt_u(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, UNSIGNED, 10);
}
static int icvt_p(FILE *f, va_list *args, int store, int width, int type){
return icvt_fixed(f, args, store, width, type, POINTER, 16);
}
#define NBUF 509
static int icvt_f(FILE *f, va_list *args, int store, int width, int type){
char buf[NBUF+1];
char *s=buf;
int c, ndig=0, ndpt=0, nexp=1;
if(width<0 || NBUF<width) width=NBUF; /* bug -- no limit specified in ansi */
do
c=ngetc(f);
while(isspace(c));
if(width--==0){
nungetc(c, f);
goto Done;
}
if(c=='+' || c=='-'){
*s++=c;
wgetc(c, f, Done);
}
while('0'<=c && c<='9' || ndpt==0 && c=='.'){
if(c=='.') ndpt++;
else ndig++;
*s++=c;
wgetc(c, f, Done);
}
if(c=='e' || c=='E'){
*s++=c;
nexp=0;
wgetc(c, f, Done);
if(c=='+' || c=='-'){
*s++=c;
wgetc(c, f, Done);
}
while('0'<=c && c<='9'){
*s++=c;
nexp++;
wgetc(c, f, Done);
}
}
nungetc(c, f);
Done:
if(ndig==0 || nexp==0) return 0;
*s='\0';
if(store) switch(type){
case 'h':
case 'n': *va_arg(*args, float *)=atof(buf); break;
case 'L': /* bug -- should store in a long double */
case 'l': *va_arg(*args, double *)=atof(buf); break;
}
return 1;
}
static int icvt_s(FILE *f, va_list *args, int store, int width, int type){
int c, nn;
register char *s;
if(store) s=va_arg(*args, char *);
do
c=ngetc(f);
while(isspace(c));
if(width--==0){
nungetc(c, f);
goto Done;
}
nn=0;
while(!isspace(c)){
if(c==EOF){
nread--;
if(nn==0) return 0;
else goto Done;
}
nn++;
if(store) *s++=c;
wgetc(c, f, Done);
}
nungetc(c, f);
Done:
if(store) *s='\0';
return 1;
}
static int icvt_c(FILE *f, va_list *args, int store, int width, int type){
int c;
register char *s;
if(store) s=va_arg(*args, char *);
if(width<0) width=1;
for(;;){
wgetc(c, f, Done);
if(c==EOF) return 0;
if(store) *s++=c;
}
Done:
return 1;
}
static int match(int c, const char *pat){
int ok=1;
if(*pat=='^'){
ok=!ok;
pat++;
}
while(pat!=fmtp){
if(pat+2<fmtp && pat[1]=='-'){
if(pat[0]<=c && c<=pat[2]
|| pat[2]<=c && c<=pat[0])
return ok;
pat+=2;
}
else if(c==*pat) return ok;
pat++;
}
return !ok;
}
static int icvt_sq(FILE *f, va_list *args, int store, int width, int type){
int c, nn;
register char *s;
register const char *pat;
pat=++fmtp;
if(*fmtp=='^') fmtp++;
if(*fmtp!='\0') fmtp++;
while(*fmtp!='\0' && *fmtp!=']') fmtp++;
if(store) s=va_arg(*args, char *);
nn=0;
for(;;){
wgetc(c, f, Done);
if(c==EOF){
nread--;
if(nn==0) return 0;
else goto Done;
}
if(!match(c, pat)){
nungetc(c, f);
goto Done;
}
if(store) *s++=c;
nn++;
}
Done:
if(store) *s='\0';
return nn > 0;
}