edit bash_tricks

This commit is contained in:
Malin Freeborn 2023-09-08 19:11:08 +02:00
parent 6f54bad403
commit b7fa4ab8c7
Signed by: andonome
GPG Key ID: 52295D2377F4D70F

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@ -12,6 +12,11 @@ See changes in a directory, as it changes:
`watch -d ls *directory*`
Or use the `-g` flag to exit once the output changes.
This command will look at whether you're connected to the internet, and turn into a rainbow once the connection hits.
> watch -g ip address && clear && ip address | lolcat
## Automatic Renaming
There are a bunch of files:
@ -34,17 +39,19 @@ done
IFS is the field separator. This is required to denote the different files as marked by a new line, and not the spaces.
(Alternatively, just install `renameutils` and do `rename Column Alice *`)
## Arguments and Input
The `rm' program takes arguments, but not `stdin' from a keyboard, and therefore programs cannot pipe results into rm.
That said, we can sometimes pipe into rm with `xargs rm' to turn the stdin into an argument. For example, if we have a list of files called `list.txt' then we could use cat as so:
To fix this, use `xargs` to turn the stdin into an argument.
For example, if we have a list of files called `list.txt' then we could use cat as so:
```bash
cat list.txt | xargs rm
```
... *However*, this wouldn't work if spaces were included, as rm would take everything literally.
Of course if spaces are included in the file, you would have to account for that.
## Numbers
@ -71,3 +78,22 @@ find . -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 15
```bash
cat /dev/urandom | tr -cd [:alnum:] | dd bs=1 count=200 status=none && echo
```
## Temporary Working Directory
Try something out in a random directory in `/tmp` so the files will be deleted when you next shut down.
```bash
mktemp -d
```
That gives you a random directory to mess about in.
```bash
dir=$(mktemp -d)
for x in {A..Z}; do
fortune > "$dir"/chimpan-$x
done
cd $dir
```