# Shell

Useful common Unix commands and tricks

## Link a binary in your local bin

```sh
ln -s -T ~/Software/GitAhead/GitAhead ~/.bin/gitahead
```

To use a physical link instead of a symlink, use `-S` instead of `-s`

## Compress

```sh
sudo tar --create --gzip --file bck_var_log.tgz --verbose /var/log
```

## Systemctl

```sh
systemctl list-units --state=failed
```

## Merge photos from others

Let's assume different people took pictures with format like `IMG_YYYYMMDD_hhmmss[suffixe].jpg` e.g. `IMG_20220713_210605__01.jpg`.

If you want to mix photos while keeping chronological order in viewers, you have to rename them in order to sort them alphabetically by date.

Use the command below to make every file start by `YYYYMMDD_hhmmss`.

### Metadata extraction

Replace `firstname` by the firstname of the person taking the picture.

```sh
exiftool -p 'mv $FileName ${CreateDate}_firstname.jpg' -d "%Y%m%d_%H%M%S" -q
 . > rename.sh
exiftool -p 'heif-convert $FileName ${CreateDate}_firstname.jpg' -d "%Y%m%d_%H%M%S" -q *.HEIC >> rename.sh
```

Then execute and remove `rename.sh`.

### Exotic formats

Some phones use HEIC, that's a weird closed format. To convert them, two ways (use the one which works) :

#### Image magick

```sh
convert 20240816_194033.heic 20240816_194033_user.jpg
```

#### Heif converter

```sh
sudo apt install libheif-examples
heif-convert -q 85 20240816_194033.heic 20240816_194033_user.jpg
```

### File name manipulations

On Ubuntu, you have two different utilities : `rename.ul` making simple replacements, and `rename` working with regex.

#### Add a name suffixe

`p1.jpg` -> `p1_suffixe.jpg`

```sh
rename.ul '.jpg' '_suffixe.jpg' *
```

#### Replace strange chars

`20220711_181620~2.jpg` -> `20220711_181620_2.jpg`

```sh
rename.ul '~' '_' *.jpg
rename.ul ')' '' *.jpg
rename.ul '(' '_' *.jpg
```

#### Device to end

`CANON_20220711_181620.jpg` -> `20220711_181620_IMG_CANON.jpg`

```sh
rename 's/(\w+)_(\d{8}_.*)\./$2_IMG_$1./' *.jpg
```

#### Device and type to end

`CANON_IMG_20220713_210605__01.jpg` -> `20220713_210605__01_IMG_CANON`
`SAM_VID_20220713_210605__01.mp4` -> `20220713_210605__01_VID_SAM.mp4`

```sh
rename 's/(\w+)_(\w{3})_(\d{8}_.*)\./$3_$2_$1/\.' *
```

#### Fix Google Pixel length

```sh
rename 's/(^PXL_.*_[0-9]{6}).*\.jpg$/$1_IMG_person.jpg/' *.jpg
rename 's/(^PXL_.*_[0-9]{6}).*\.mp4$/$1_IMG_person.mp4/' *.mp4
rename.ul -- 'PXL_' '' *
```

Take care, timestamp seems to be in UTC.