The UNIX® Standard | www. opengroup. org Single UNIX Specification- “The Standard” The Single UNIX Specification is the standard in which the core interfaces of a UNIX OS are measured The UNIX standard includes a rich feature set, and its core volumes are simultaneously the IEEE Portable Operating System Interface (POSIX) standard and the ISO IEC 9945 standard
What does the line #! bin sh mean in a UNIX shell script? When you try to execute a program in unix (one with the executable bit set), the operating system will look at the first few bytes of the file These form the so-called "magic number", which can be used to decide the format of the program and how to execute it
unix - What is the meaning of POSIX? - Stack Overflow Since every Unix does things a little differently -- Solaris, Mac OS X, IRIX, BSD, and Linux all have their quirks -- POSIX is especially useful to those in the industry as it defines a standard environment to operate in
unix - Why is 1 1 1970 the epoch time? - Stack Overflow The definition of unix time and the epoch date went through a couple of changes before stabilizing on what it is now But it does not say why exactly 1 1 1970 was chosen in the end