https://github.com/karlhorky/command-line-tricks

A collection of useful command line tricks
https://github.com/karlhorky/command-line-tricks

command-line terminal

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A collection of useful command line tricks

• Host: GitHub
• URL: https://github.com/karlhorky/command-line-tricks
• Owner: karlhorky
• Created: 2015-10-12T10:07:12.000Z (about 9 years ago)
• Default Branch: main
• Last Pushed: 2024-10-11T09:08:55.000Z (about 1 month ago)
• Last Synced: 2024-10-20T06:21:40.362Z (24 days ago)
• Topics: command-line, terminal
• Homepage:
• Size: 12.7 KB
• Stars: 4
• Watchers: 2
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: readme.md

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README

        
# Command Line Tricks

A collection of useful command line tricks

## Create File with Content

To create a file including content (overwriting the file if it exists), use `echo` with the `-e` flag (to allow for escape sequences like the `\n` newline) and redirect to a file with `>`:

```bash

echo -e 'abc\ndef' > 1.txt

```

Now `1.txt` will include the following content:

```

abc

def

```

To make multi-line content more readable, use `cat` with a heredoc tag like `EOF`:

```bash

cat << EOF > main.ts

import { add } from './add.js';

console.log(add(2,3));

EOF

```

## FFmpeg: Combine two video files

Combine two video files using [FFmpeg](https://ffmpeg.org/)

```bash

ls video1.mp4 video2.mp4 | while read line; do echo file \'$line\'; done | ffmpeg -protocol_whitelist file,pipe -f concat -i - -c copy output.mp4

```

Source: [How to concatenate two MP4 files using FFmpeg? (Answer) | Stack Overflow](https://stackoverflow.com/a/61151377/1268612)

## Find and Replace in Git Remote

Sometimes you may want to search and replace within your Git remote - for example, if you change your username on GitHub. This is a command to do it (replaces `OldUsername` with `NewUsername`):

```sh

git remote set-url origin $(current_origin=$(git remote get-url origin --push) && echo ${current_origin/OldUsername/NewUsername})

```

## gzip web assets

Loop over CSS, JS, EOT, SVG and TTF files and gzip them into a folder named `gzipped`.

`gzip-web-assets.sh`

```bash

#!/usr/bin/env bash

# Usage:

# $ ./gzip-web-assets.sh

mkdir gzipped

for file in $(find . -type f -depth 1 | egrep "\.(css|js|eot|svg|ttf)$") ; do

  gzip -c --best $file > gzipped/$file

done

```