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 includes a rich feature …
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 number", …
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?
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 defines a …
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 which …
Converting unix time into date-time via excel - Stack Overflow
Explanation Unix system represent a point in time as a number. Specifically the number of seconds* since a zero-time called the Unix epoch which is 1/1/1970 00:00 UTC/GMT. This number of seconds …
unix - How can I pretty-print JSON in a shell script? - Stack Overflow
Dec 9, 2008 · I've created an alias: alias pretty='python -mjson.tool | pygmentize -l json so that I can just run: command params | pretty. Hope this helps. PS: Should anyone manages to extend this to a) …
unix - How to comment out particular lines in a shell script - Stack ...
Aug 21, 2013 · Can anyone suggest how to comment particular lines in the shell script other than #? Suppose I want to comment five lines. Instead of adding # to each line, is there any other way to …
How to convert DOS/Windows newline (CRLF) to Unix newline (LF)
Apr 10, 2010 · How can I programmatically (not using vi) convert DOS/Windows newlines to Unix newlines? The dos2unix and unix2dos commands are not available on certain systems. How can I …
unix - How to check permissions of a specific directory ... - Stack ...
I know that using ls -l "directory/directory/filename" tells me the permissions of a file. How do I do the same on a directory? I could obviously use ls -l on the directory higher in the hierarchy...