diff options
| -rw-r--r-- | src/string/strverscmp.c | 57 |
1 files changed, 25 insertions, 32 deletions
diff --git a/src/string/strverscmp.c b/src/string/strverscmp.c index 6f37cc68..4daf276d 100644 --- a/src/string/strverscmp.c +++ b/src/string/strverscmp.c @@ -2,40 +2,33 @@ #include <ctype.h> #include <string.h> -int strverscmp(const char *l, const char *r) +int strverscmp(const char *l0, const char *r0) { - int haszero=1; - while (*l==*r) { - if (!*l) return 0; + const unsigned char *l = (const void *)l0; + const unsigned char *r = (const void *)r0; + size_t i, dp, j; + int z = 1; - if (*l=='0') { - if (haszero==1) { - haszero=0; - } - } else if (isdigit(*l)) { - if (haszero==1) { - haszero=2; - } - } else { - haszero=1; - } - l++; r++; + /* Find maximal matching prefix and track its maximal digit + * suffix and whether those digits are all zeros. */ + for (dp=i=0; l[i]==r[i]; i++) { + int c = l[i]; + if (!c) return 0; + if (!isdigit(c)) dp=i+1, z=1; + else if (c!='0') z=0; } - if (haszero==1 && (*l=='0' || *r=='0')) { - haszero=0; - } - if ((isdigit(*l) && isdigit(*r) ) && haszero) { - size_t lenl=0, lenr=0; - while (isdigit(l[lenl]) ) lenl++; - while (isdigit(r[lenr]) ) lenr++; - if (lenl==lenr) { - return (*l - *r); - } else if (lenl>lenr) { - return 1; - } else { - return -1; - } - } else { - return (*l - *r); + + if (l[dp]!='0' && r[dp]!='0') { + /* If we're not looking at a digit sequence that began + * with a zero, longest digit string is greater. */ + for (j=i; isdigit(l[j]); j++) + if (!isdigit(r[j])) return 1; + if (isdigit(r[j])) return -1; + } else if (z && dp<i && (isdigit(l[i]) || isdigit(r[i]))) { + /* Otherwise, if common prefix of digit sequence is + * all zeros, digits order less than non-digits. */ + return (unsigned char)(l[i]-'0') - (unsigned char)(r[i]-'0'); } + + return l[i] - r[i]; } |