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 which …

2021年10月27日 · Furthermore, you also have || which is the logical or, and also ; which is just a separator which doesn't care what happend to the command before.

If not quoted, it is a pattern match! (From the Bash man page: "Any part of the pattern may be quoted to force it to be matched as a string."). Here in Bash, the two statements yielding "yes" are pattern …

2017年1月27日 · I realize you said “read the bash man pages” but at first, I thought you meant read the man pages within bash. At any rate, man bash returns a huge file, which is 4139 lines (72 pages) long.

2010年2月10日 · Bash always seemed backward with numeric evaluations using an operator consisting of a string (-eq) and string comparisons using a numeric operator "==" or "=" just you mess you up. If …

Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification. If you're in an environment where you have to be strictly POSIX compliant, stay …

The switches -a and -n are not strictly part of a bash if statement in that the if command does not process these switches. What are primaries? I call them "switches", but the bash documentation that …

When writing shell programs, we often use /bin/sh and /bin/bash. I usually use bash, but I don't know what's the difference between them. What's the main difference between Bash and sh? What do we ...

2016年3月10日 · Using Bash's own regex-matching operator, =~, is a faster alternative in this case, given that you're only matching a single value already stored in a variable:

2017年1月30日 · #!/bin/bash # To focus exclusively on the performance of each type of increment # statement, we should exclude bash performing while loops from the # performance measure.