How to cut (select) a field from text line counting from the end?
I know how to select a field from a line using the cut command. For instance, given the following data:
shell
Replacing only specific variables with envsubst
I’m trying to perform environment variable replacement through envsubst, but I want to only replace specific variables.
Why is ‘.’ a hard link in Unix?
I’ve seen many explanations for why the link count for an empty directory in Unix based OSes is 2 instead of 1. They all say that it’s because of the ‘.’ directory, which every directory has pointing back to itself. I understand why having some concept of ‘.’ is useful for specifying relative paths, but what is gained by implementing it at the filesystem level? Why not just have shells or the system calls that take paths know how to interpret it?
How to understand the order between expansions?
From POSIX 7:
Performance differences between pipelines and process substitution
I tend to use pipelines in my bash scripts over process substitution in most situations, especially in cases of using multiple sets of commands as it seems more readable to do ... | ... | ... over ... < <(... < <(...)).
How can I search for a file with fixed name length using ls?
In a directory, I have files like
Run a command when system is idle and when is active again
I want to run a command when the user becomes inactive (the system is idle). For example:
How do I display all the characters between two specific strings?
I want to display all the characters in a file between strings “xxx” and “yyy” (the quotes are not part of the delimiters). How can I do that ? For example, if i have input “Hello world xxx this is a file yyy”, the output should be ” this is a file “
Is it shell portable to run a command on the same line after variable assignment?
Is there any standard that covers the portability of running a command after variable assignment on the same line?
How to move the first x files
I have this huge folder with thousands of unordered files. Is it feasible to move the first 5000s to a subfolder via the mv command? For now I move files with