| #include "format.h" |
| #include <stdint.h> |
| typedef struct {char *data;size_t capacity,used;} OUTPUT; |
| static void put(OUTPUT *o,char c) {if(o->used+1<o->capacity)o->data[o->used]=c;o->used++;} |
| size_t GuFormatV(char *destination,size_t capacity,const char *format,va_list args) { |
| OUTPUT o={destination,capacity,0}; |
| if(!format || (capacity && !destination))return SIZE_MAX; |
| while(*format) { |
| if(*format!='%'){put(&o,*format++);continue;}format++; |
| unsigned width=0,length=0,base=10;int alternate=0,zero=0,negative=0; |
| while(*format=='#' || *format=='0'){if(*format=='#')alternate=1;else zero=1;format++;} |
| while(*format>='0' && *format<='9') { |
| width=width*10+(unsigned)(*format++-'0');if(width>128)goto invalid; |
| } |
| if(*format=='l'){length=1;format++;if(*format=='l'){length=2;format++;}} |
| else if(*format=='z'){length=3;format++;} |
| char kind=*format;if(!kind)goto invalid;format++; |
| if(kind=='s') { |
| if(length || alternate || zero || width)goto invalid; |
| const char *s=va_arg(args,const char *);if(!s)s="(null)";while(*s)put(&o,*s++);continue; |
| } |
| if(kind=='c' || kind=='%') { |
| if(length || alternate || zero || width)goto invalid; |
| put(&o,kind=='%'?'%':(char)va_arg(args,int));continue; |
| } |
| uint64_t value; |
| if(kind=='d' || kind=='i') { |
| int64_t signed_value; |
| if(length==2)signed_value=va_arg(args,long long); |
| else if(length==1)signed_value=va_arg(args,long); |
| else if(length==3)signed_value=va_arg(args,ptrdiff_t); |
| else signed_value=va_arg(args,int); |
| negative=signed_value<0;value=negative?0-(uint64_t)signed_value:(uint64_t)signed_value; |
| } else if(kind=='u' || kind=='x' || kind=='X') { |
| if(length==2)value=va_arg(args,unsigned long long); |
| else if(length==1)value=va_arg(args,unsigned long); |
| else if(length==3)value=va_arg(args,size_t); |
| else value=va_arg(args,unsigned int); |
| if(kind!='u')base=16; |
| } else goto invalid; |
| char digits[32];unsigned n=0;int prefix=alternate && base==16 && value; |
| const char *alphabet=kind=='X'?"0123456789ABCDEF":"0123456789abcdef"; |
| do {digits[n++]=alphabet[value%base];value/=base;}while(value); |
| unsigned total=n+(negative?1U:0U)+(prefix?2U:0U),pad=width>total?width-total:0; |
| if(!zero)while(pad){put(&o,' ');pad--;} |
| if(negative)put(&o,'-');if(prefix){put(&o,'0');put(&o,kind=='X'?'X':'x');} |
| if(zero)while(pad){put(&o,'0');pad--;} |
| while(n)put(&o,digits[--n]); |
| } |
| if(capacity)destination[o.used<capacity?o.used:capacity-1]=0;return o.used; |
| invalid: |
| if(capacity)destination[0]=0;return SIZE_MAX; |
| } |
|
|
