razzius / reference

personal how-to collection

Remove one directory level of path string in shell script

cut -d / -f 2-

$ echo a/b/c | cut -d / -f 2-
b/c

Remove first word delimited by spaces in shell script

cut -d ' ' -f 2-

$ head -1 README.md | cut -d ' ' -f 2-
Remove one directory level of path string in shell script

Match regex string in fish

string match -r

$ if string match -rq 'vim?' $EDITOR
   echo vi or vim
end
vi or vim

Slice string in fish

echo $var[1..3]

Called "index range expansion". Works on whole lines.

Since fish 3.2 the end index is optional.

$ echo (seq 3)[2..]
2 3

To slice within a line, use string split ' ' first.

$ echo (echo a b c | string split ' ')[2..]
b c

Move a directory into the current directory, overwriting a local directory of the same name

rsync --archive --delete <source> <destination>

The issue arises in the following directory structure:

$ tree
.
├── dir-a
│   └── dir-b
│       └── some_file
└── dir-b
    └── useless_file

3 directories, 2 files

# mv errors instead of overwriting dir-b
$ mv dir-a/dir-b/ .
mv: rename dir-a/dir-b/ to ./dir-b/: Directory not empty

# explicitly passing ./dir-b just puts the files in ./dir-b, creating a nested dir-b:
$ mv dir-a/dir-b/ ./dir-b
$ tree
.
├── dir-a
└── dir-b
    ├── dir-b
    │   └── some_file
    └── useless_file

3 directories, 2 files

Vim search for whole word

/\<word\> (though starting with < is usually enough)

This is so that for example eat isn't found in create.

Vim command that runs multiple commands

Tell the first that it can be followed with another using -bar:

command! -bar Terminal terminal

Then create a command that uses | to run multiple commands:

command! FullscreenTerminal Terminal|:only

Source

tree do not show summary

tree --noreport

$ tree --noreport
.
└── dir
    └── some_file

funcsave to current directory

funcsave -d . (from man funcsave)

$ function commit
      git-add-commit (echo (cat README.md | grep '###' | tail -1 | string split ' ')[2..])
  end
$ funcsave -d . commit
$ git stat
## main...origin/main
?? commit.fish

Github website submit comment and close issue

⌘ shift enter

How to make fish script executable

Start with #!/usr/bin/env fish

Check if argument is executable in fish

type -q zoxide

(Using zoxide as an example)

How to make less always run with -R flag

export LESS="-R"

How to parse and access named arguments with fish

$ function arg_test
    argparse d/directory= -- $argv
    echo $_flag_directory
  end
$ arg_test -d 3
3

See n/name=.

n/name= means that both -n and --name are valid. It requires a value and can be used at most once. If the flag is seen then _flag_n and _flag_name will be set with the single mandatory value associated with the flag.

How to show git diff inline, by words

git diff --color-words

Decimal to hex in shell

printf %x <number>

$ printf %x 10
a

Delete a range of lines in vim ex

:6,13d

Print decimal as hex with leading zero, as necessary

printf("%02x")

$ printf %02x 15
0f

Can vim be made to accept - instead of , in range specification?

Open question #1

Why does dividing a 16-bit number by 257 convert it to 8-bit?

Open question #2

How to make dir different for 1 command in fish?

Open question #3

How to do inline parenthesized commands in fish?

Open question #4

Vim call function in key remap

nnoremap <leader>ih :call MyFunction()<cr>

link

How to open emacs with no config file

emacs -q

How to open emacs in terminal

emacs -nw

How to sleep in mysql to make an artificially slow query

select sleep(5)