{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Interacting with the Command Line Shell"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Basic Linux Commands"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "mkdir mynewdir\n",
    "cd mynewdir/\n",
    "/mynewdir$ pwd\n",
    "/mynewdir$ cp ../spider.txt .\n",
    "/mynewdir$ touch myfile.txt\n",
    "/mynewdir$ ls -l \n",
    "#Output:\n",
    "#-rw-rw-r-- 1 user user   0 Mai 22 14:22 myfile.txt\n",
    "#-rw-rw-r-- 1 user user 192 Mai 22 14:18 spider.txt\n",
    "/mynewdir$ ls -la\n",
    "#Output:\n",
    "#total 12\n",
    "#drwxr-xr-x  2 user user  4096 Mai 22 14:17 .\n",
    "#drwxr-xr-x 56 user user 12288 Mai 22 14:17 ..\n",
    "#-rw-rw-r--  1 user user     0 Mai 22 14:22 myfile.txt\n",
    "#-rw-rw-r--  1 user user   192 Mai 22 14:18 spider.txt\n",
    "/mynewdir$ mv myfile.txt emptyfile.txt\n",
    "/mynewdir$ cp spider.txt yetanotherfile.txt\n",
    "/mynewdir$ ls -l\n",
    "#Output:\n",
    "#total 8\n",
    "#-rw-rw-r-- 1 user user   0 Mai 22 14:22 emptyfile.txt\n",
    "#-rw-rw-r-- 1 user user 192 Mai 22 14:18 spider.txt\n",
    "#-rw-rw-r-- 1 user user 192 Mai 22 14:23 yetanotherfile.txt\n",
    "/mynewdir$ rm *\n",
    "/mynewdir$ ls -l\n",
    "#total 0\n",
    "/mynewdir$ cd ..\n",
    "rmdir mynewdir/\n",
    "ls mynewdir\n",
    "#ls: cannot access 'mynewdir': No such file or directory\n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Redirecting streams"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "cat stdout_example.py \n",
    "#!/usr/bin/env python3\n",
    "print(\"Don't mind me, just a bit of text here...\")\n",
    "./stdout_example.py \n",
    "#Output: Don't mind me, just a bit of text here...\n",
    "./stdout_example.py > new_file.txt\n",
    "cat new_file.txt \n",
    "#Output: Don't mind me, just a bit of text here...\n",
    "./stdout_example.py >> new_file.txt\n",
    "cat new_file.txt \n",
    "#Output: Don't mind me, just a bit of text here...\n",
    " #Don't mind me, just a bit of text here...\n",
    "cat streams_err.py \n",
    "#!/usr/bin/env python3\n",
    "\n",
    "data = input(\"This will come from STDIN: \")\n",
    "print(\"Now we write it to STDOUT: \" + data)\n",
    "raise ValueError(\"Now we generate an error to STDERR\")\n",
    "./streams_err.py < new_file.txt\n",
    "#This will come from STDIN: Now we write it to STDOUT: Don't mind #me, just a bit of text here...\n",
    "#Traceback (most recent call last):\n",
    "  #File \"./streams_err.py\", line 5, in <module>\n",
    "    #raise ValueError(\"Now we generate an error to STDERR\")\n",
    "#ValueError: Now we generate an error to STDERR\n",
    "./streams_err.py < new_file.txt 2> error_file.txt\n",
    "#This will come from STDIN: Now we write it to STDOUT: Don't mind #me, just a bit of text here...\n",
    "cat error_file.txt \n",
    "#Traceback (most recent call last):\n",
    "  #File \"./streams_err.py\", line 5, in <module>\n",
    "    #raise ValueError(\"Now we generate an error to STDERR\")\n",
    "#ValueError: Now we generate an error to STDERR\n",
    "echo \"These are the contents of the file\" > myamazingfile.txt\n",
    "cat myamazingfile.txt \n",
    "#These are the contents of the file\n"
   ]
  }
 ],
 "metadata": {
  "language_info": {
   "name": "python"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}