diff options
Diffstat (limited to 'lib9/strtoll.c')
| -rw-r--r-- | lib9/strtoll.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/lib9/strtoll.c b/lib9/strtoll.c new file mode 100644 index 00000000..ff98e1c4 --- /dev/null +++ b/lib9/strtoll.c @@ -0,0 +1,81 @@ +#include "lib9.h" + +vlong +strtoll(const char *nptr, char **endptr, int base) +{ + const char *p; + vlong n; + int c, v, neg, ndig; + + p = nptr; + neg = 0; + n = 0; + ndig = 0; + + /* + * White space + */ + for(;;p++){ + switch(*p){ + case ' ': + case '\t': + case '\n': + case '\f': + case '\r': + case '\v': + continue; + } + break; + } + + /* + * Sign + */ + if(*p=='-' || *p=='+') + if(*p++ == '-') + neg = 1; + + /* + * Base + */ + if(base==0){ + if(*p != '0') + base = 10; + else{ + base = 8; + if(p[1]=='x' || p[1]=='X'){ + p += 2; + base = 16; + } + } + }else if(base==16 && *p=='0'){ + if(p[1]=='x' || p[1]=='X') + p += 2; + }else if(base<0 || 36<base) + goto Return; + + /* + * Non-empty sequence of digits + */ + for(;; p++,ndig++){ + c = *p; + v = base; + if('0'<=c && c<='9') + v = c - '0'; + else if('a'<=c && c<='z') + v = c - 'a' + 10; + else if('A'<=c && c<='Z') + v = c - 'A' + 10; + if(v >= base) + break; + n = n*base + v; + } + Return: + if(ndig == 0) + p = nptr; + if(endptr) + *endptr = (char*) p; + if(neg) + return -n; + return n; +} |
