Merge branch 'master' of github.com:charlesreid1/hello-world

* 'master' of github.com:charlesreid1/hello-world: updating http.awk to be http_get.awk removing java widget (moving to hello-oop repo) updating list of programs in master readme updating bash http GET script and factorial. corresponding updates to readme. moving C http get from http to http_get rearranging bash hello world script as a function improve message printing for Awk Simpsons Rule updating Awk http server script add simpsons rule integral calculator in Awk
8 years ago · e69cdc44de
11 changed files with 207 additions and 62 deletions
--- a/README.md
+++ b/README.md
@ -47,25 +47,38 @@ What time is it:
				@@ -47,25 +47,38 @@ What time is it:

 Factorial:
 * Implements the factorial function: `4! = 4*3*2*1`
-* http://rosettacode.org/wiki/Factorial
-
-
-### List of Programs In Progress
+* Uses iterative and recursive versions

 HTTP Get:
 * Implements accessing an HTTP resource using get
-* http://rosettacode.org/wiki/HTTP
+* [Link](http://rosettacode.org/wiki/HTTP)

 HTTP Server:
 * Implements running an http server 
-* https://rosettacode.org/wiki/Hello_world/Web_server
+* [Link](https://rosettacode.org/wiki/Hello_world/Web_server)
+
+Calculus: Simpson's Rule for Integration
+* Implements composite Simpson's Rule to integrate a function over an interval `[a,b]` using `n` approximating points
+
+
+### Programs In Progress

+HTTP Post:
+* Access an API using POST request

+Algebra: Log and Trig Tables
+* Print out logarithm and trigonometric tables
+* Exercises trigonometric functions, formatted print functionality, loops

-### List of Programs To Implement
+Calculus: Taylor Series Approximation of Sine Function
+* Implements a Taylor Series to approximate a sine function

-Pi/Sqrt/Logs:
-* Print out a log table, square root table, pi, etc.
+Calculus: Newton's Method
+* Implements Newton's Method to compute the roots of an arbitrary function f(x)
+
+
+
+### Programs To Implement

 Arrays:
 * Use a native built-in data type to store a 1D array of data
@ -86,4 +99,3 @@ Calculus:
				@@ -86,4 +99,3 @@ Calculus:
 * Compute the numerical integral of a function
 * Integrate a differential equation

-
--- a/awk/README.md
+++ b/awk/README.md
@ -10,6 +10,14 @@ $ awk -f hello_world.awk
				@@ -10,6 +10,14 @@ $ awk -f hello_world.awk
 Hello world!
 ```

+## What Time Is It?
+
+Prints the current date and time using built-in awk functions (strftime).
+
+```
+$ awk -f what_time_is_it.awk
+```
+
 ## 99 Bottles

 Prints the lyrics to the 99 Bottles of Beer on the Wall song:
@ -52,6 +60,54 @@ Take one down, pass it around.
				@@ -52,6 +60,54 @@ Take one down, pass it around.
 [...]
 ```

+## HTTP Get
+
+This file will get a webpage using an HTTP GET request. Run the script like this:
+
+```
+$ awk -f http_get.awk
+
+HTTP/1.1 200 OK
+Server: nginx/1.9.3 (Ubuntu)
+Date: Thu, 09 Mar 2017 19:45:26 GMT
+Content-Type: text/html; charset=UTF-8
+Connection: close
+X-Content-Type-Options: nosniff
+Content-language: en
+X-UA-Compatible: IE=Edge
+Vary: Accept-Encoding,Cookie
+Expires: Thu, 01 Jan 1970 00:00:00 GMT
+Cache-Control: private, must-revalidate, max-age=0
+Last-Modified: Sun, 19 Feb 2017 21:59:32 GMT
+
+<!DOCTYPE html>
+<html lang="en" dir="ltr" class="client-nojs">
+<head>
+<meta charset="UTF-8" />
+<title>charlesreid1</title>
+```
+
+
+## HTTP Post
+
+This will send a POST request to a server. Specifically, this will call a URL and pass POST data with the request.
+
+```
+$ awk -f http_post.awk
+```
+
+
+## HTTP Server
+
+Yes, you can abuse awk, a text manipulation scripting language, to run a web server. This utilizes networking capabilities deep within the bowels of awk.
+
+The following script listens for a single request on port 8080. Once the user has visited localhost:8080, awk responds with an HTTP 200 OK code, and a "Hello World" page. 
+Once the page has been returned, the script will die; the HTTP server is not persistent.
+
+```
+awk -f http_server.awk
+```
+
 ## Factorial

 Print the factorial of a number (12 by default). Edit to change it to your own number. To run:
@ -62,27 +118,12 @@ $ awk -f factorial.awk
				@@ -62,27 +118,12 @@ $ awk -f factorial.awk
 12! = 479001600
 ```

-## HTTP Get
+## Simpson's Rule

-This file will get a webpage using an HTTP Get request. 
+This integrates the function `sin(x)` from 0 to pi/2 (the result should be exactly 1) using Simpson's composite rule and a user-specified number of sample points.

 ```
-$ awk -f http.awk HTTP/1.1 301 TLS Redirect
-
-Server: Varnish
-Location: https://en.wikipedia.org/wiki/Apollo_11
-Content-Length: 0
-Accept-Ranges: bytes
-Date: Thu, 28 Jul 2016 06:40:42 GMT
-X-Varnish: 1997612095
-Age: 0
-Via: 1.1 varnish
-Connection: close
-X-Cache: cp1053 int
-Set-Cookie: WMF-Last-Access=28-Jul-2016;Path=/;HttpOnly;secure;Expires=Mon, 29 Aug 2016 00:00:00 GMT
-X-Client-IP: 209.95.50.128
-Cache-Control: private, s-maxage=0, max-age=0, must-revalidate
-Set-Cookie: GeoIP=US:NY:New_York:40.74:-74.00:v4; Path=/; secure; Domain=.wikipedia.org
+awk -f simpsons_rule.awk
 ```


@ -90,3 +131,4 @@ Set-Cookie: GeoIP=US:NY:New_York:40.74:-74.00:v4; Path=/; secure; Domain=.wikipe
				@@ -90,3 +131,4 @@ Set-Cookie: GeoIP=US:NY:New_York:40.74:-74.00:v4; Path=/; secure; Domain=.wikipe



+
--- a/awk/http_get.awk
+++ b/awk/http_get.awk
--- a/awk/http_server.awk
+++ b/awk/http_server.awk
@ -1,14 +1,26 @@
				@@ -1,14 +1,26 @@
+# This program runs an HTTP server on port 8080.
+# It will listen for a single connection, send an HTTP response, then die.
 BEGIN {
-  RS = ORS = "\r\n"
-  HttpService = "/inet/tcp/8080/0/0"
-  Hello = "<HTML><HEAD>" \
-          "<TITLE>A Famous Greeting</TITLE></HEAD>" \
-          "<BODY><H1>Hello, world</H1></BODY></HTML>"
-  Len = length(Hello) + length(ORS)
-  print "HTTP/1.0 200 OK"          |& HttpService
-  print "Content-Length: " Len ORS |& HttpService
-  print Hello                      |& HttpService
-  while ((HttpService |& getline) > 0)
-     continue;
-  close(HttpService)
+    RS = ORS = "\r\n"
+
+    # Reach into the bowels of awk
+    HttpService = "/inet/tcp/8080/0/0"
+
+    # Prepare the HTML response
+    Hello = "<HTML><HEAD>" \
+            "<TITLE>A Famous Greeting</TITLE></HEAD>" \
+            "<BODY><H1>Hello, world</H1></BODY></HTML>"
+
+    # Return the response to the HTTP service
+    Len = length(Hello) + length(ORS)
+    print "HTTP/1.0 200 OK"          |& HttpService
+    print "Content-Length: " Len ORS |& HttpService
+    print Hello                      |& HttpService
+
+    # Now wait for a response
+    while ((HttpService |& getline) > 0)
+        continue;
+
+    # Close it out
+    close(HttpService)
 }
--- a/awk/simpsons_rule.awk
+++ b/awk/simpsons_rule.awk
@ -0,0 +1,50 @@
				@@ -0,0 +1,50 @@
+# Define a way for us to assert something is true
+function assert(condition, string)
+{
+    if (! condition) {
+        printf("%s:%d: assertion failed: %s\n",
+            FILENAME, FNR, string) > "/dev/stderr"
+        _assert_exit = 1
+        exit 1
+    }
+}
+
+# The function we are integrating - sin(x)
+function f(x) {
+    return sin(x)
+}
+
+# Simpson's rule:
+# Integrates f(x) from a to b, using n intervals
+function simpsons_rule(a,b,n) { 
+    # a = lower bound of integral 
+    # b = upper bound of integral
+    # n = number of partitions on the interval
+    assert(n%2==0,"n%2==0")
+    s1 = 0.0
+    s2 = 0.0
+    sum = 0.0
+    h = (b - a) / n 
+    for(i=1; i<=n; i++) {
+        x_i = a * i*h
+        if(i%2==0) {
+            s1 += f(x_i)
+        } else {
+            s2 += f(x_i)
+        }
+    }
+    sum = (h/3.0)*(f(a) + f(b) + 2*s1 + 4*s2)
+    return sum
+}
+
+BEGIN {
+    printf("Simpson's Rule Integral Calculation:")
+    printf("Integrating sin(x) from 0 to pi/2\n")
+    pi = atan2(0, -1)
+    a = 0.0
+    b = pi/2
+    for(n = 10; n<=100000; n*=10) {
+        result = simpsons_rule(a,b,n)
+        printf("%d segments: int(sin(x)) = %0.8f \n",n,result)
+    }
+}
--- a/bash/README.md
+++ b/bash/README.md
@ -12,7 +12,12 @@ Prints a message to the screen. Uses the echo function:
				@@ -12,7 +12,12 @@ Prints a message to the screen. Uses the echo function:

 ## 99 Bottles

-Shows off how we concatenate strings, increment numbers, convert types, and call functions.
+Utilizes functions to print out various pieces of a message. This prints "99 Bottles of Beer" with correct punctuation.
+
+```
+./99bottles.sh
+```
+

 ## What Time Is It

@ -22,25 +27,32 @@ Prints the current date and time. Uses the date utility:
				@@ -22,25 +27,32 @@ Prints the current date and time. Uses the date utility:
 ./what_time_is_it.sh
 ```

-### Http Server

-Runs a web server at port 8080. Uses netcat `nc`:
+## HTTP Get
+
+Get a URL using curl.

 ```
-./http_server.sh
+./http_get.sh
 ```

-Warning: this process can't be killed with Control+C.
-Use Control-Z, then look for the process (`ps aux | grep nc`), 
-then kill the process (`kill -9 <PID>`).

-## HTTP Get
+## HTTP Post

-Get a URL using curl.
+Send POST data to a URL using curl. 

 ```
-./http.sh
+./http_post.sh
+```
+
+
+### HTTP Server
+
+Runs a web server at port 8080. Uses netcat `nc`:
+
+```
+./http_server.sh
 ```

-Not sure if I should be saving to a file........
+### Factorial

--- a/bash/factorial.sh
+++ b/bash/factorial.sh
@ -0,0 +1,17 @@
				@@ -0,0 +1,17 @@
+#!/bin/bash
+
+function factorial() {
+    n=${1}
+    echo "$n"
+    if [ "$n" -eq "1" ]
+    then
+        return 1
+    else
+        factorial $((n-1))
+        fact=$?
+        # Do n times fact
+        echo "${fact}"
+    fi
+}
+
+factorial 5
--- a/bash/hello_world.sh
+++ b/bash/hello_world.sh
@ -1,3 +1,12 @@
				@@ -1,3 +1,12 @@
 #!/bin/bash

-echo "Hello world!"
+function hello_world {
+    echo "Hello world!"
+}
+
+function hello_name {
+    echo "Hello world! This is ${1}"
+}
+
+hello_world
+hello_name "Robot Gerald Ford"
--- a/bash/http_get.sh
+++ b/bash/http_get.sh
--- a/c/http_get.c
+++ b/c/http_get.c
@ -14,7 +14,7 @@ main(void)
				@@ -14,7 +14,7 @@ main(void)
        char buffer[CURL_ERROR_SIZE];
 
 		// use curl library
-		// following libcurl.org documentation/example
+		// following example provided in libcurl.org documentation 
        if ((curl = curl_easy_init()) != NULL) {
                curl_easy_setopt(curl, CURLOPT_URL, "http://www.wikipedia.org/en/Apollo_11");
                curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
--- a/java/Widget.java
+++ b/java/Widget.java
@ -1,9 +0,0 @@
				@@ -1,9 +0,0 @@
-public class Widget {
-    private String message;
-    public Widget() {
-        this.message = "Hello object-world!";
-    }
-    public void printMessage() {
-        System.out.println( this.message );
-    }
-}