> For the complete documentation index, see [llms.txt](https://benhurott.gitbook.io/appsecben/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://benhurott.gitbook.io/appsecben/tools/bash-scripting.md).

# Bash Scripting

### Foreach in Cat File

```bash
# my_script.sh
cat deps.txt | while read line
do
   echo "$line"
done
```

### Output to cmd and file at the same time

```bash
# the command output will be displaied to the terminal
# and will be writen in the myfile.txt
my_comand | tee myfile.txt
```

### Check if command exists

```bash
command_exists () {
    if [[ $(command -v $1) ]]; then
        return 0
    fi

    return 1
}

if command_exists "MyCommandHere"; then
    echo "MyCommandHere exists"
fi


# real world sample

if command_exists "exa"; then
    alias ls="exa"
fi
```


---

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