diff options
Diffstat (limited to 'contrib/syslinux-4.02/dos/strntoumax.c')
-rw-r--r-- | contrib/syslinux-4.02/dos/strntoumax.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/dos/strntoumax.c b/contrib/syslinux-4.02/dos/strntoumax.c new file mode 100644 index 0000000..d8bc73b --- /dev/null +++ b/contrib/syslinux-4.02/dos/strntoumax.c @@ -0,0 +1,73 @@ +/* + * strntoumax.c + * + * The strntoumax() function and associated + */ + +#include <stddef.h> +#include <stdint.h> +#include <ctype.h> + +static inline int digitval(int ch) +{ + if (ch >= '0' && ch <= '9') { + return ch - '0'; + } else if (ch >= 'A' && ch <= 'Z') { + return ch - 'A' + 10; + } else if (ch >= 'a' && ch <= 'z') { + return ch - 'a' + 10; + } else { + return -1; + } +} + +uintmax_t strntoumax(const char *nptr, char **endptr, int base, size_t n) +{ + int minus = 0; + uintmax_t v = 0; + int d; + + while (n && isspace((unsigned char)*nptr)) { + nptr++; + n--; + } + + /* Single optional + or - */ + if (n && *nptr == '-') { + minus = 1; + nptr++; + n--; + } else if (n && *nptr == '+') { + nptr++; + } + + if (base == 0) { + if (n >= 2 && nptr[0] == '0' && (nptr[1] == 'x' || nptr[1] == 'X')) { + n -= 2; + nptr += 2; + base = 16; + } else if (n >= 1 && nptr[0] == '0') { + n--; + nptr++; + base = 8; + } else { + base = 10; + } + } else if (base == 16) { + if (n >= 2 && nptr[0] == '0' && (nptr[1] == 'x' || nptr[1] == 'X')) { + n -= 2; + nptr += 2; + } + } + + while (n && (d = digitval(*nptr)) >= 0 && d < base) { + v = v * base + d; + n--; + nptr++; + } + + if (endptr) + *endptr = (char *)nptr; + + return minus ? -v : v; +} |