{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Text and arithmetic in `bash`"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Working with text streams\n",
    "    - `stdin`, `stdout`, `sterr`\n",
    "    - `>`, `>>`, `<`\n",
    "    - `|`\n",
    "    - `echo`\n",
    "    - `cat`\n",
    "    - `HEREDOCS`\n",
    "    - `printf`\n",
    "    - `cut`\n",
    "    - `sort`\n",
    "    - `uniq`\n",
    "    - brace expansions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "echo 'Hello' > foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "echo 'Goodbye' >> foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello\n",
      "Goodbye\n"
     ]
    }
   ],
   "source": [
    "cat foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello\n",
      "Goodbye\n"
     ]
    }
   ],
   "source": [
    "cat foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello\n",
      "Goodbye\n"
     ]
    }
   ],
   "source": [
    "cat < foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "cat > bar.txt <<EOF\n",
    "One\n",
    "Two\n",
    "Three\n",
    "EOF"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "One\n",
      "Two\n",
      "Three\n"
     ]
    }
   ],
   "source": [
    "cat bar.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "cat > bar.txt <<EOF\n",
    "One\n",
    "Two\n",
    "Three\n",
    "EOF |"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Two\n"
     ]
    }
   ],
   "source": [
    "head -2 bar.txt | tail -1 "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello world again"
     ]
    }
   ],
   "source": [
    "printf 'Hello %s again' world"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 inch is     2.54 centimeters"
     ]
    }
   ],
   "source": [
    "printf '%d inch is %8.2f centimeters' 1 2.54"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 inch is 2.54     centimeters"
     ]
    }
   ],
   "source": [
    "printf '%d inch is %-8.2f centimeters' 1 2.54"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5 feet 1 inches is 152.5 centimeters"
     ]
    }
   ],
   "source": [
    "FEET=5\n",
    "INCH=1\n",
    "CM_IN_FEET=30\n",
    "CM_IN_INCH=2.54\n",
    "RESULT=$(echo \"$FEET * $CM_IN_FEET + $INCH * $CM_IN_INCH\"  | bc)\n",
    "printf '%d feet %d inches is %.1f centimeters' $FEET $INCH $RESULT"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "##\n",
      "# User Database\n",
      "# \n"
     ]
    }
   ],
   "source": [
    "cat /etc/passwd | head -3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "##\n",
      "# User Database\n",
      "# \n"
     ]
    }
   ],
   "source": [
    "cut -f1 -d: /etc/passwd | head -3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "##\n",
      "# User Database\n",
      "# \n"
     ]
    }
   ],
   "source": [
    "cut -f2 -d/ /etc/passwd | head -3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\n",
      "Use\n",
      "\n"
     ]
    }
   ],
   "source": [
    "cut -c3-5 /etc/passwd | head -3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "#\n",
      "# \n",
      "# \n",
      "# Note that this file is consulted directly only when the system is running\n",
      "# Open Directory.\n"
     ]
    }
   ],
   "source": [
    "cut -f1 -d: /etc/passwd | sort | head -5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "root\n",
      "nobody\n",
      "daemon\n",
      "_xgridcontroller\n",
      "_xgridagent\n"
     ]
    }
   ],
   "source": [
    "cut -f1 -d: /etc/passwd | sort -r | head -5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "##\n",
      "# User Database\n",
      "# \n",
      "# Note that this file is consulted directly only when the system is running\n",
      "# in single-user mode.  At other times this information is provided by\n"
     ]
    }
   ],
   "source": [
    "cut -f3 -d: /etc/passwd | head -5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "99\n",
      "98\n",
      "97\n",
      "96\n",
      "95\n"
     ]
    }
   ],
   "source": [
    "cut -f3 -d: /etc/passwd | sort -r | head -5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "214\n",
      "213\n",
      "212\n",
      "211\n",
      "210\n"
     ]
    }
   ],
   "source": [
    "cut -f3 -d: /etc/passwd | sort -nr | head -5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-rw-r--r--  1 cliburn  staff  1207075 Oct 17 10:28 face.png\n",
      "-rw-r--r--  1 cliburn  staff  1067008 Oct 30 13:44 Chinook_Sqlite.sqlite\n",
      "-rw-r--r--  1 cliburn  staff   470003 Oct 17 10:31 Python06C.ipynb\n",
      "-rw-r--r--  1 cliburn  staff   435109 Oct 29 11:50 Python08A.ipynb\n",
      "-rw-r--r--  1 cliburn  staff   279122 Nov  2 09:31 Python09B.ipynb\n",
      "-rw-r--r--  1 cliburn  staff   173446 Oct 30 13:44 Python09A.ipynb\n",
      "-rw-r--r--  1 cliburn  staff   161864 Oct  7 10:18 Python07B.ipynb\n",
      "-rw-r--r--@ 1 cliburn  staff    41276 Sep 19 08:29 Python01.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    40464 Sep 21 19:45 Python03.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    34613 Oct  6 17:57 Python06A.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    27355 Sep 27 08:54 Python05.ipynb\n",
      "-rw-r--r--@ 1 cliburn  staff    27153 Sep 21 08:09 Python02.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    24515 Oct  6 19:29 Python07A.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    22925 Sep 29 09:01 Python04B.ipynb\n",
      "-rw-r--r--@ 1 cliburn  staff    22784 Sep 12 09:33 UnixShell03.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    22266 Oct  6 18:05 Python06B.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    14210 Oct 30 13:44 tips.xlsx\n",
      "-rw-r--r--  1 cliburn  staff    13814 Sep 29 09:01 Python04A.ipynb\n",
      "-rw-r--r--@ 1 cliburn  staff    12974 Sep  5 09:03 UnixShell02.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    11642 Oct 31 07:16 Python9A_Exercise.ipynb\n",
      "-rw-r--r--  1 cliburn  staff    11068 Oct  3 10:49 Python06.ipynb\n",
      "-rw-r--r--  1 cliburn  staff     5929 Oct 31 07:21 Python9B_Exercise.ipynb\n",
      "-rw-r--r--  1 cliburn  staff     5117 Sep 12 09:37 UnixShell04.ipynb\n",
      "-rw-r--r--  1 cliburn  staff     3203 Aug 31 19:19 UnixShell01.ipynb\n",
      "-rw-r--r--  1 cliburn  staff  361 Oct 23 16:23 mystery.cpython-36.pyc\n",
      "-rw-r--r--  1 cliburn  staff      135 Oct 23 16:23 mystery.py\n",
      "-rw-r--r--  1 cliburn  staff       14 Nov  2 11:25 foo.txt\n",
      "-rw-r--r--  1 cliburn  staff       14 Nov  2 11:25 bar.txt\n",
      "total 8\n",
      "total 2360\n",
      "figs:\n",
      "__pycache__:\n",
      "\n",
      "\n"
     ]
    }
   ],
   "source": [
    "ls -l * | sort -rn -k 5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n"
     ]
    }
   ],
   "source": [
    "echo '3 2 1 2 3 1 4 5 5' | tr ' ' '\\n'  | sort -n | uniq"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "bar.txt baz.txt\n"
     ]
    }
   ],
   "source": [
    "echo ba{r,z}.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ls: baz.txt: No such file or directory\n",
      "-rw-r--r--  1 cliburn  staff  14 Nov  2 11:25 bar.txt\n"
     ]
    },
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "ls -l ba{r,z}.txt"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Regular expressions\n",
    "    - patterns\n",
    "    - direct match\n",
    "    - alternatives\n",
    "    - character sets\n",
    "    - named character sets\n",
    "    - word boundaries\n",
    "    - numeric qualifiers\n",
    "    - capture groups"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "match\n"
     ]
    }
   ],
   "source": [
    "[[ 'abc' =~ 'abc' ]] && echo 'match' || echo 'no match'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "no match\n"
     ]
    }
   ],
   "source": [
    "[[ 'abc' =~ 'cba' ]] && echo 'match' || echo 'no match'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "TEXT1=\"123-ABC-123-xyz\"\n",
    "TEXT2=\"123-ABC-321-xyz\"\n",
    "\n",
    "PATTERN=\"([0-9]+)-[A-Z]+-\\1-[a-z]+\"\n",
    "\n",
    "[[ ${TEXT1} =~ ${PATTERN} ]] && [[ ! ${TEXT2} =~ ${PATTERN} ]] && echo 'match'"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Finding stuff\n",
    "    - `find`\n",
    "    - `grep`\n",
    "    - Combining `find` and `grep`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "./bar.txt\n",
      "./foo.txt\n"
     ]
    }
   ],
   "source": [
    "find . -name \"*.txt\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "One\n",
      "Two\n",
      "Three\n",
      "cat: baz.txt: No such file or directory\n",
      "Hello\n",
      "Goodbye\n"
     ]
    },
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "cat bar.txt baz.txt foo.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "cat: noise.py: No such file or directory\n"
     ]
    },
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "cat noise.py"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "grep 'while' *py"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "./UnixShell02.ipynb:    \"grep -r 'sleep' .\"\n",
      "./UnixShell02.ipynb:    \"grep -r -n --exclude=\\\"*.ipynb\\\" 'sleep' .\"\n",
      "./UnixShell03.ipynb:    \"    sleep 1\\n\",\n",
      "./UnixShell03.ipynb:    \"    sleep 1\\n\",\n",
      "./UnixShell03.ipynb:    \"    sleep 1\\n\",\n"
     ]
    }
   ],
   "source": [
    "grep -r 'sleep' ."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {
    "scrolled": false
   },
   "outputs": [
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "grep -r -n --exclude=\"*.ipynb\" 'sleep' ."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "./bar.txt:One\n"
     ]
    }
   ],
   "source": [
    "find . -name \"*.txt\" | xargs grep -i \"one\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Modifying stuff\n",
    "    - `tr`\n",
    "    - `sed`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gattaca\n"
     ]
    }
   ],
   "source": [
    "echo 'GATTACA' | tr 'ACTG' 'actg' "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "GAUUACA\n"
     ]
    }
   ],
   "source": [
    "echo 'GATTACA' | tr 'ACTG' 'ACUG'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "CACGGCT\n"
     ]
    }
   ],
   "source": [
    "echo 'GATTACA' | tr 'ACTG' 'CAGT' | rev "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "tHE QUICK BROWN FOX\n"
     ]
    }
   ],
   "source": [
    "echo 'The quick brown fox' | tr 'A-Za-z' 'a-zA-Z'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "vJG SWKEM DTQYP HQZ\n"
     ]
    }
   ],
   "source": [
    "echo 'The quick brown fox' | tr 'A-Za-z' 'c-zabC-ZAB'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The quick brown fox\n"
     ]
    }
   ],
   "source": [
    "echo 'The quick brown fox' | tr 'A-Za-z' 'c-zabC-ZAB' | tr 'c-zabC-ZAB' 'A-Za-z' "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "cat: baz.txt: No such file or directory\n"
     ]
    },
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "cat bar.txt baz.txt foo.txt > big.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "One\n",
      "Two\n",
      "Three\n",
      "Hello\n",
      "Goodbye\n"
     ]
    }
   ],
   "source": [
    "cat big.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "One\n",
      "Two\n",
      "Three\n"
     ]
    }
   ],
   "source": [
    "cat big.txt | sed 4,6d"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 46,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "One\n",
      "Two\n",
      "Three\n",
      "Hello\n",
      "Goodbye\n"
     ]
    }
   ],
   "source": [
    "cat big.txt | sed /'^ '/d"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "sed: 1: \"/o/Ip\": invalid command code I\n"
     ]
    },
    {
     "ename": "",
     "evalue": "1",
     "output_type": "error",
     "traceback": []
    }
   ],
   "source": [
    "cat big.txt | sed -n /'o'/Ip"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 48,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "cat > humpty.txt <<EOF\n",
    "Humpty Dumpty sat on a wall,\n",
    "Humpty Dumpty had a big fall.\n",
    "All the king's horses and all the king's men\n",
    "Couldn't put Humpty together again\n",
    "EOF"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "H[XXX]ty Dumpty sat on a wall,\n",
      "H[XXX]ty Dumpty had a big fall.\n",
      "All the king's horses and all the king's men\n",
      "Couldn't put H[XXX]ty together again\n"
     ]
    }
   ],
   "source": [
    "sed s/'u.p'/'[XXX]'/ humpty.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 50,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "H[XXX]ty D[XXX]ty sat on a wall,\n",
      "H[XXX]ty D[XXX]ty had a big fall.\n",
      "All the king's horses and all the king's men\n",
      "Couldn't put H[XXX]ty together again\n"
     ]
    }
   ],
   "source": [
    "sed s/'u.p'/'[XXX]'/g humpty.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 51,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Humpty Dumpty sat on a wall,\n",
      "H[XXX]ty D[XXX]ty had a big fall.\n",
      "All the king's horses and all the king's men\n",
      "Couldn't put Humpty together again\n"
     ]
    }
   ],
   "source": [
    "sed /fall/s/'u.p'/'[XXX]'/g humpty.txt"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Humpty Dumpty sat on a wall,\n",
      "Humpty D[XXX]ty had a big fall.\n",
      "All the king's horses and all the king's men\n",
      "Couldn't put Humpty together again\n"
     ]
    }
   ],
   "source": [
    "sed /fall/s/'u.p'/'[XXX]'/2 humpty.txt"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- Working with arithmetic expressions\n",
    "    - `seq`\n",
    "    - Integer arithmetic\n",
    "    - Floating point arithmetic"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 53,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1,2,3,4,5,"
     ]
    }
   ],
   "source": [
    "seq 5 | tr '\\n' ', '"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 54,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3,4,5,6,7,"
     ]
    }
   ],
   "source": [
    "seq 3 7  | tr '\\n' ', '"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 55,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3,5,7,"
     ]
    }
   ],
   "source": [
    "seq 3 2 7  | tr '\\n' ', '"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1,1.2,1.4,1.6,1.8,2,"
     ]
    }
   ],
   "source": [
    "seq 1 0.2 2  | tr '\\n' ', '"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 57,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5\n"
     ]
    }
   ],
   "source": [
    "echo $((2 + 3))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 58,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Experiment_001.txt\n",
      "Experiment_002.txt\n",
      "Experiment_003.txt\n",
      "Experiment_004.txt\n",
      "Experiment_005.txt\n"
     ]
    }
   ],
   "source": [
    "for IDX in $(seq 5); do\n",
    "    FILENAME=$(printf \"Experiment_%03d.txt\" ${IDX})\n",
    "    echo $FILENAME\n",
    "done"
   ]
  }
 ],
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  "kernelspec": {
   "display_name": "Bash",
   "language": "bash",
   "name": "bash"
  },
  "language_info": {
   "codemirror_mode": "shell",
   "file_extension": ".sh",
   "mimetype": "text/x-sh",
   "name": "bash"
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