What does $# mean in shell? I have code such as if [ $# -eq 0 ] then I want to understand what $# means, but Google search is very bad for searching these kinds of things.

2011年2月20日 · When going through one shell script, I saw the term "$?". What is the significance of this term?$? expands to the exit status of the most recently executed …

2012年5月8日 · I understand the basic difference between an interactive shell and a non-interactive shell. But what exactly differentiates a login shell from a non-login shell? Can you …

2025年8月2日 · When it comes to shell scripts it's difficult to support both short options and long options. I usually pick one or the other and use getopt or getopts as appropriate. This makes …

2020年4月5日 · Lets say I SSH to my linux shell. Inside it I want to run a program that will run for 8 hours: I create a "detached screen" by entering screen and then crtl+a, crtl+d to deattach it. …

In shell terminology, eval is a built-in, not a function. In practice, built-ins behave a lot like functions that don't have an in-language definition, but not quite (as becomes apparent if you …

I have a file, f1.txt: ID Name 1 a 2 b 3 g 6 f The number of spaces is not fixed. What is the best way to replace all the white spaces with one space using only tr? ...

2017年2月24日 · 3.win+x打开控制面板，在右上角输入管理工具，找到组件服务右键以管理员身份运行，依次展开组件服务→计算机→我的电脑→DCOM配置，找打Immersive Shell右键点击属 …

2017年9月1日 · The command that -exec can execute is limited to an external utility with optional arguments. To use shell built-ins, functions, conditionals, pipelines, redirections etc. directly …

2018年10月17日 · When .ONESHELL is not used Makefile executes each shell commands in a separate shell. What is the benefit of this? Why doesn't makefile uses the same shell?