You don’t need and you should never write code like that – especially if you’re not a C compiler / standard library vendor. It is code used to implement strlen with some very questionable speed hacks and assumptions (that are not tested with assertions or mentioned in the comments): unsigned long is either 4 or … Read more
By the C standard, the compiler is free to store the bit field pretty much in any random way it wants. You can never make any assumptions of where the bits are allocated. Here are just a few bit-field related things that are not specified by the C standard: Unspecified behavior The alignment of the … Read more
Since we can’t find a version on the Internet, let’s start one here. Most ports to Windows probably only need a subset of the complete Unix file. Here’s a starting point. Please add definitions as needed. #ifndef _UNISTD_H #define _UNISTD_H 1 /* This is intended as a drop-in replacement for unistd.h on Windows. * Please … Read more
After some attempts i finally get a workaround to bundle the jre in my application: I package my app as a zip file with the following folders inside: containerFolder |- jre |-bin (in bin there is java.exe) |-lib |- cfg (to save the user configuration, but it’s not needed) |- bin (my application with the … Read more
There is no ANSI C function that provides better than 1 second time resolution but the POSIX function gettimeofday provides microsecond resolution. The clock function only measures the amount of time that a process has spent executing and is not accurate on many systems. You can use this function like this: struct timeval tval_before, tval_after, … Read more
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
Look at getpass module import getpass getpass.getuser() ‘kostya’ Availability: Unix, Windows p.s. Per comment below “this function looks at the values of various environment variables to determine the user name. Therefore, this function should not be relied on for access control purposes (or possibly any other purpose, since it allows any user to impersonate any … Read more
Welcome to the wonderful world of portability… or rather the lack of it. Before we start analyzing these two options in detail and take a deeper look how different operating systems handle them, it should be noted that the BSD socket implementation is the mother of all socket implementations. Basically all other systems copied the … Read more
Including <bits/stdc++.h> appears to be an increasingly common thing to see on Stack Overflow, perhaps something newly added to a national curriculum in the current academic year. I imagine the advantages are vaguely given thus: You only need write one #include line. You do not need to look up which standard header everything is in. … Read more