From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.5) Gecko/20011013 Description of problem: The following program does not work: #include <stdio.h> main () { long s; unsigned long us; sscanf("0xF0F0F0F0", "%lu", &us); if (us != 0xf0f0f0f0) printf("fail unsigned: expect 0xf0f0f0f0 got 0x%lx\n", us); sscanf("0xF0F0F0F0", "%li", &s); if (s != 0xf0f0f0f0) printf("fail signed: expect 0xf0f0f0f0 got 0x%lx\n", s); } Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. Compile the sample code and run it. Actual Results: The output from the sample code is: fail unsigned: expect 0xf0f0f0f0 got 0x0 fail signed: expect 0xf0f0f0f0 got 0x7fffffff Expected Results: The conversion should have worked. Additional info: I am using glibc-2.2.4-19.3
glibc is right, please reread info libc on formated input. %u conversion matches unsigned integer in DECIMAL radix (so it matches 0 but not the rest) - this is strtoul (, , 10) does. %i conversion matches optionally signed integer in decimal/octal/hex radix, is what strtol (, , 0) does. But in this second case the problem is that you're trying to put an value which doesn't fit into 32-bit signed integer (errno is set to ERANGE after second sscanf).