The UNIX® Standard | www.opengroup.org
May 22, 2025 · 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 …
What does the line "#!/bin/sh" mean in a UNIX shell script?
Sep 10, 2011 · 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 …
unix - what does '$?' mean in a shell script? - Stack Overflow
Oct 5, 2012 · I came across a shell script that contains a statement like, if [ $val -eq $? ] What does $? mean here?
What are the special dollar sign shell variables? - Stack Overflow
Sep 14, 2012 · In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process …
What is the proper way to exit a command line program?
2 Take a look at Job Control on UNIX systems If you don't have control of your shell, simply hitting ctrl + C should stop the process. If that doesn't work, you can try ctrl + Z and using the jobs …
unix - What is the meaning of "POSIX"? - Stack Overflow
Nov 23, 2009 · 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 …
Boolean operators ( &&, -a, ||, -o ) in Bash - Stack Overflow
Dec 8, 2013 · What is the difference between the &&, ||, -a, and -o Unix operators? What are the restrictions on the usage of both types? Is it simply that the && and || operators should be used ...
How can I send an email through the UNIX mailx command?
Feb 17, 2010 · From the man page: Sending mail To send a message to one or more people, mailx can be invoked with arguments which are the names of people to whom the mail will be …
Newest 'unix' Questions - Stack Overflow
Currently there is a unix-based system that exposes a file in what the team is saying would be {{parameters.secret-path}}/file. I am not sure how to read that in java given the enclosing of …
UNIX® Certification Program | www.opengroup.org
UNIX certification is a trusted and open system industry standard, ensuring that products conform to the most exacting criteria for portability, compatibility, and global interoperability.