What are the special dollar sign shell variables?
2012年9月14日 · In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process …
linux - Explaining the 'find -mtime' command - Stack Overflow
2014年8月27日 · The POSIX specification for find says:-mtimen The primary shall evaluate as true if the file modification time subtracted from the initialization time, divided by 86400 (with …
unix - what does '$?' mean in a shell script? - Stack Overflow
2012年10月5日 · unix; Share. Improve this question. Follow asked Oct 5, 2012 at 7:38. Raj Raj. 4,442 12 12 gold badges 42 ...
The UNIX® Standard | www.opengroup.org
2024年9月16日 · 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 …
Find all files containing a specific text (string) on Linux?
2013年6月6日 · find is the standard tool for searching files - combined with grep when looking for specific text - on Unix-like platforms. The find command is often combined with xargs , by the …
What does the line "#!/bin/sh" mean in a UNIX shell script?
2011年9月10日 · 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 …
scripting - What does $$ mean in the shell? - Stack Overflow
2008年9月17日 · Every process in a UNIX like operating system has a (temporarily) unique identifier, the PID. No two processes running at the same time can have the same PID, and $$ …
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. This …
linux - How can I recursively find all files in current and subfolders ...
2011年5月5日 · The default way to search for files recursively, and available in most cases is. find . -name "filepattern" It starts recursively traversing for filename or pattern from within the …
Newest 'unix' Questions - Stack Overflow
here is what I'm trying to do.. I'm trying to cat a text file and display the full file and only changing some characters (which are appearing in other lines also), and use grep to match the key …