An example of how to use getopts in bash
Example runs:
bash
How to grep for case insensitive string in a file?
You can use the -i flag which makes your pattern case insensitive: Also, there is no need for cat. grep takes a file with the syntax grep <pattern> <file>. I also used the -F flag to search for a fixed string to avoid escaping the ellipsis.
-bash: syntax error near unexpected token `)’
It is not possible to escape single quote in single quotes. Use ” ” instead Also, there are other ways to deal with this problem: All these should print quote’test as a single parameter. Which means that another great solution for your problem is: I have only placed a dollar sign $ right before the … Read more
How to concatenate string variables in Bash
In general to concatenate two variables you can just write them one after another:
How do I use a regex in a shell script?
I think this is what you want: I’ve used the -P switch to get perl regex.
In the shell, what does ” 2>&1 ” mean?
File descriptor 1 is the standard output (stdout).File descriptor 2 is the standard error (stderr). Here is one way to remember this construct (although it is not entirely accurate): at first, 2>1 may look like a good way to redirect stderr to stdout. However, it will actually be interpreted as “redirect stderr to a file named 1“. & indicates that what follows and precedes is … Read more
What does export PS1=”\[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$ ” mean in MacOS’ bash Terminal?
export is used to set environment variable in operating system. This variable will be available to all child processes created by current Bash process ever after. PS1 is the primary prompt which is displayed before each command, thus it is the one most people customize. read more: https://wiki.archlinux.org/index.php/Bash/Prompt_customization#Prompts And the statement: \[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$dictates how the prompt is going to look … Read more
How to decode Seagate’s hard drive date code in a Bash script
This is what I did, it should work: It worked for the two dates given above… If you want to customize the date output, add a format string at the end of the FINALDATe assignment.
“Couldn’t find a file descriptor referring to the console” on Ubuntu bash on Windows
I’m new in here and it’s my first post. I have a problem with Bash on Ubuntu on Windows. If I type “open (filename)” on Mac terminal, it opens the file with the right program but if I try to use it on Windows bash, it says: “Couldn’t find a file descriptor referring to the … Read more
Why do you need to put #!/bin/bash at the beginning of a script file?
It’s a convention so the *nix shell knows what kind of interpreter to run. For example, older flavors of ATT defaulted to sh (the Bourne shell), while older versions of BSD defaulted to csh (the C shell). Even today (where most systems run bash, the “Bourne Again Shell”), scripts can be in bash, python, perl, … Read more