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Lectures schedule
When ? Topic Lecture
October 26, 2014 Introduction to C Programming in Unix Environment - I
1
November 2, 2014 Introduction to C Programming in Unix Environment - II
2
November 9, 2014 Introduction to Assembly 3
November 16, 2014 Functions and System Calls (Assembly) 4
Midterm A (December 9, 2014 - 18:00)
December 7, 2014 Unix Processes 5
December 14, 2014 Programs Execution 6
December 28, 2014 Introduction to script languages (Python) + ELF
7
January 4, 2014 Web programming 8
Midterm B (January 19, 2015) OR (January 20, 2015)
3
Revisit ELFNavigate through the Maze
4
Current state
C and Assembly – Efficient code with access to OS services
Shell Scripts – connecting Unix utilities by I/O redirection and pipes
5
Glue language
In practice, programs output needs pre-processing
Usually an interpreted scripting language
Useful for writing and maintaining: custom commands for a command shell wrapper programs for executables
C/Java VS. Python
6
Exampleimport java.io.IOException;import java.io.FileReader;import java.io.BufferedReader;
class numlines {public static void main(String[] args) throws IOException {BufferedReader inp = new BufferedReader(new FileReader(args[0]));String line;for(int i=1;;++i) { line = inp.readLine(); if(line==null)
break; System.out.printf("%3d: %s\n", i, line);}inp.close();
}}-------------------------------------------------------------------------------------------import sys
i = 1for line in file(sys.argv[1]):
print "%3d: %s" % (i, line),i+= 1
7
Python
An open source interpreted programming language
High-level language Object-Oriented Functional Programming
Suitable for scripting
Practical ( VS. Efficiency )
Dynamic language
8
Variables
No need to declare
Not typed
greeting = "hello world"greeting = 12**2print greeting
Need to assign (initialize)▪ use of uninitialized variable raises exception
9
Strings
"hello"+"world" "helloworld" # concatenation
"hello"*3 "hellohellohello" # repetition
"hello"[0] "h" # indexing
"hello"[-1] "o" # (from end)
"hello"[1:4] "ell" # slicing
len("hello") 5 # size
"hello" < "jello" 1 # comparison
"e" in "hello" 1 # search
10
Tuples
key = (lastname, firstname)
point = (x, y, z) # parentheses optional
a,b,c = point # unpack
lastname = key[0]
sort of an immutable list key[1] = ‘Abed’ #TypeError: 'tuple' object does not support item
assignment
11
Lists
[<elements>]
>>> my_list = ['Hello', 1, 2.2, 'world']>>> len(my_list)4>>> my_list[0]‘Hello’>>> my_list.append(‘espl’)>>> my_list >>> ['Hello', 1, 2.2, 'world‘,’espl’]>>> del my_list[0]>>> [1, 2.2, 'world‘,’espl’]>>> my_list.index(‘espl’)>>> 4>>> ‘espl141’ in my_list>>> False
12
Dictonary
Hash tables, "associative arrays" d = {"duck": "eend", "water": “cold"}
Lookup: d["duck"] -> "eend" d["back"] # raises KeyError exception
Keys, values, items: d.keys() -> ["duck", “water"] d.values() -> [“eend", “cold"] d.items() -> [("duck",“eend"), (“water",“cold")]
Presence check: d.has_key("duck") -> 1; d.has_key("spam") -> 0
13
Functions
def <function_name>(<arguments>): <body>
def factorial(n): fact = 1 for i in range(1, n):
fact = fact * i
return fact
14
Classes
class student: def __init__(self, id):
self._id = id self._grades = {}
def update_grade(self, subject, grade): self._grades[subject] = grade
#Comment, Main:s = student('233445598')
s.update_grade('heshbon', 80) s.update_grade('handasa', 49)
15
Modules
>>> from math import * >>> sin(30*3.14/180)
>>> from math import sin >>> sin(30*3.14/180)
>>> from math import sin as sinus >>> sinus(30*3.14/180)
16
And More …
Control structures If statement While For ….
