diff options
Diffstat (limited to 'libntp/hextoint.c')
-rw-r--r-- | libntp/hextoint.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/libntp/hextoint.c b/libntp/hextoint.c new file mode 100644 index 0000000..0d774eb --- /dev/null +++ b/libntp/hextoint.c @@ -0,0 +1,39 @@ +/* + * hextoint - convert an ascii string in hex to an unsigned + * long, with error checking + */ +#include <ctype.h> + +#include "ntp_stdlib.h" + +int +hextoint( + const char *str, + u_long *ival + ) +{ + register u_long u; + register const char *cp; + + cp = str; + + if (*cp == '\0') + return 0; + + u = 0; + while (*cp != '\0') { + if (!isxdigit((int)*cp)) + return 0; + if (u >= 0x10000000) + return 0; /* overflow */ + u <<= 4; + if (*cp <= '9') /* very ascii dependent */ + u += *cp++ - '0'; + else if (*cp >= 'a') + u += *cp++ - 'a' + 10; + else + u += *cp++ - 'A' + 10; + } + *ival = u; + return 1; +} |