According to the standard (§6.4.4.4/10) The value of an integer character constant containing more than one character (e.g., ‘ab’), […] is implementation-defined. long x = ‘\xde\xad\xbe\xef’; // yes, single quotes This is valid ISO 9899:2011 C. It compiles without warning under gcc with -Wall, and a “multi-character character constant” warning with -pedantic. From Wikipedia: Multi-character … Read more
The chdir function works on both POSIX (manpage) and Windows (called _chdir there but an alias chdir exists). Both implementations return zero on success and -1 on error. As you can see in the manpage, more distinguished errno values are possible in the POSIX variant, but that shouldn’t really make a difference for most use … Read more
I think this is the relevant clause: ISO/IEC 14882:2003 C++ Standard 23.1.1/12 – Sequences Table 68 lists sequence operations that are provided for some types of sequential containers but not others. An implementation shall provide these operations for all container types shown in the “container” column, and shall implement them so as to take amortized … Read more
It should be noted that MSVC uses the syntax: #pragma message ( “your warning text here” ) The usual #warning syntax generates a fatal error C1021: invalid preprocessor command ‘warning’ so it is not portable to those compilers.
#!/usr/bin/env python is more portable because in general the program /usr/bin/env can be used to “activate” the desired command without full path. Otherwise, you would have to specify the full path of the Python interpreter, which can vary. So no matter if the Python interpreter was in /usr/bin/python or in /usr/local/bin/python or in your home … Read more
Try using ftp.nlst(dir). However, note that if the folder is empty, it might throw an error: files = [] try: files = ftp.nlst() except ftplib.error_perm as resp: if str(resp) == “550 No files found”: print “No files in this directory” else: raise for f in files: print f
#define htonll(x) ((1==htonl(1)) ? (x) : ((uint64_t)htonl((x) & 0xFFFFFFFF) << 32) | htonl((x) >> 32)) #define ntohll(x) ((1==ntohl(1)) ? (x) : ((uint64_t)ntohl((x) & 0xFFFFFFFF) << 32) | ntohl((x) >> 32)) The test (1==htonl(1)) simply determines (at runtime sadly) if the hardware architecture requires byte swapping. There aren’t any portable ways to determine at compile-time what … Read more
In python 2.6 it is portable if the CPU supports it The float() function will now turn the string nan into an IEEE 754 Not A Number value, and +inf and -inf into positive or negative infinity. This works on any platform with IEEE 754 semantics.
The function getenv is the only one specified by the C standard. The function putenv, and the extern environ are POSIX-specific. EDIT The main parameter envp is not specified by POSIX but is widely supported. An alternative method of accessing the environment list is to declare a third argument to the main() function: int main(int … Read more
A method that is portable to most POSIX systems is: raise(SIGTRAP);