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https://askubuntu.com/q/875471
Title:
Why is ls -R called "recursive" listing?
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/2017/01/24/Why-is-ls-R-called-_recursive_-listing_
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January 24, 2017
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April 8, 2024
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-R is for recursion, which could loosely be called “repeatedly”.
Take this code for example:
───────────────────────────────────────────────────────────────────────────────
$ mkdir -p temp/a
───────────────────────────────────────────────────────────────────────────────
$ mkdir -p temp/b/1
───────────────────────────────────────────────────────────────────────────────
$ mkdir -p temp/c/1/2
───────────────────────────────────────────────────────────────────────────────
$ ls -R temp
temp:
a b c
temp/a:
temp/b:
1
temp/b/1:
temp/c:
1
temp/c/1:
2
temp/c/1/2:
The -p in making directories allows you to mass create directories with a single command. If one or more of the top-middle directories already exist it’s not an error and the middle-lower directories are created.
Then the ls -R recursively lists every single directory starting with temp and working it’s way down the tree to all the branches.
Now let’s look at a complement to the ls -R command, ie the tree command:
$ tree temp
temp
├── a
├── b
│ └── 1
└── c
└── 1
└── 2
6 directories, 0 files
As you can see tree accomplishes the same as ls -R except is more concise and dare I say “prettier”.
Now let’s look at how to recursively remove the directories we just created in one simple command:
$ rm -r temp
This recursively removes temp and all the sub-directories underneath it. ie temp/a, temp/b/1 and temp/c/1/2 plus the middle directories in between.