Raesel's Opus
Spring Semester 2012
This is my second course here at the lair and I am looking forward to it. I am still a computer science major with interest in software engineering and, more enthusiastically, aerospace engineering. My status is a freshmore here at CCC. I do plan to transfer to a four year school for my bachelor degree and possibly look into getting my masters degree.
Random information about me: I like to wear fedora hats and you will almost never see me without one. I am passionate about movies and and embarking on an adventure to rewrite Macbeth and make it into a movie. I like to bake and occasionally cook savory foods. I do enjoy listening to music… on occasion. I love to travel to exotic locales. I am also an avid couch potato.
Today we played more with pointers. We wrote another program which delved into the realm of double pointers. I think I understand pointers but I may be over-simpplifing them. Esssentialy, they direct the computer to another location. When called to give the information contained in them they return the value of what they are pointing to.
Todday we wrote a game in class. We used some elements of things that we used in previous classes as well as looked into loops. We also looked at the rand function which is supposed to resemble a random number generator but doesn't do it very well. We did go through and fix the problem which did make it more random. We also added a loop into the code which looped the game until the user decides to quit. I understand this program and what it is doing, which is a good sign. I haven't gotten lost in the class yet which is always a hopeful start.
Today we looked at arrays. My previous experince with arrays is limited to the theoretical realm. I understood that arrays needed to be sized before you start to fill them but I never was quite sure how to actually create them in a program. Today's class helped. I am still not 100% comfortable with creating them on my own but I do see how it can be done.
Today Project 1 was due and it was rather more challenging than previously thought. I understand the logic of how to do the program and I understand what needs to be done on the project, however, I am struggling with the actual implementation of the code. When I sit to write the code I essentially draw a blank and have no idea where to begin. I believe that if I sit down more with a pseudocode and play more with syntax and read source material on how to code in C I can overcome this dilemma. Otherwise, this will be a very difficut semester.
(STDIO, STDOUT, STDERR)
The main libraries in which C programs run
#include <stdio.h>
AND, OR, NOT, XOR
Specifies the parameters of the loop and determines if the loop should execute
while((x!='\0')&&(x!='\n'))
This is an AND operator in a program
taking one form of variable and making it fit into another form of variable
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
#include <stdio.h> #include <stdlib.h> int main() { int *p1, *p2, p3, **p4; p1=(int*)malloc(sizeof(int)*1); *p1=26; printf("*p1 is %u\n", *p1); p2=p1; p4=&p1; printf("**p4 is %u\n",**p4); printf("*p2 is %u\n",*p2); *p2=61; printf("*p1 is %u\n", *p1); printf("**p4 is %u\n", **p4); printf("*p2 is %u\n", *p2); return(0); }
This allocated memory in the size of an int
Sets the memory address for something
#include <stdio.h> int main() { int a=0; int *b; b=&a; *b=12; printf("a contains %u\n", a); printf("a's address is 0x%x\n", &a); printf("b contains %u\n", *b); printf("b points to 0x%x\n", b); printf("b's address is 0x%x\n", &b); return(0); }
b is a pointer to a
Holds many different elements of the same data type at one address
#include <stdio.h> #include <stdlib.h> int main() { char *word, len=0, x, pos=0; word=(char *)malloc(sizeof(char)*24); fprintf(stdout, "Please enter a word: "); fscanf(stdin, "%s", word); printf("Debug A\n"); x=*(word+pos); printf("Debug A1\n"); while((x!='\0')&&(x!='\n')) { printf("in the while, x is %hhd\n",x); len++; pos++; x=*(word+pos); } printf("Debug B\n"); for(pos=0; pos<len; pos++) { fprintf(stdout, "%c", *(word+pos)-32);
read, write append
Creating a file and reading it into a program or writing the output of a program to a file
#include <stdio.h> #include <stdlib.h> int main() { FILE *in, *out; char value=0; in=fopen("file.txt", "r"); out=fopen("out.txt", "w"); if(in==NULL) { printf("ERROR!\n"); exit(1); n, *out; char value=0; in=fopen("file.txt", "r"); out=fopen("out.txt", "w"); if(in==NULL) if(in==NULL) if(in==NULL) } fscanf(in, "%hhd", &value); while(value !=-1) { value *=2; fprintf(out,"%hhd\n", value); fscanf(in, "%hhd", &value); } fclose(in); fclose(out); return(0); }
for, while, do while
These are loops that govern how many times a program will execute a certain task
/* * Sample code block */ #include <stdio.h> int main() { int v; while v!=0 { printf("Rise against the machines\n"); } else { printf(The machines have won\n") } return(0); }
Libraries
These are the #include statements at the beginning of a program. They are needed so that certain commands can be understood by the compiler to run a program
#include <stdio.h> #include <stdlib.h> #include <math.h>
There are others but these are just a few
comprehend the basics of memory management, data representation and storage
Can the student understand how to allocate memory and represent what they wish to represent with the proper file type? Does the student understand how to store values in C?
Explain the code of project 0
The code of project 0 is defining the size of the storage available for the different types of arguments in C. Each storage size dictates how much memory needs to be allocated for that type and whether or not datat will fit into that storage type.
I understand the logic behind most codes but will need to continue to work on writing the actual code.
Can a program check the upper and lower bounds
Class notes and book
Yes. The program can check the upper
Write a code
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
signed int input;
char column=0;
char row=0;
printf("Enter a value (0-4): ");
scanf("%d", &input);
while((input<4) && (input>0))
{
printf("argv[%hhu]: %c\n", input, *(*(argv+row)+column));
printf("You ran this program with %hhu arguments, they are:\n",argc);
exit(1);
}
printf("You have input an invalid value\n");
return(0);
}
I know that the code should work but I am unable to get the right syntax to compile it.
I need to spend more time learning syntax.
What happens if you put a semicolon on the end of a loop statement
the book was consulted
The program won't compile
I will add a semicolon on the end of a loop statement in a program and see what happens
The program didn't compile. The loop statement was treated like another regular statement in the program which threw the whole program off.
The hypothesis was correct although I could have gone much further into figuring out why it would not compile. The hypothesis short cited and lacks depth.
Although the program behaved as expected it could have been explore further.
What types of things create a segmentation fault
class programs and book
Faulty syntax will cause a seg fault
Play with codes already written
I found that mainly a logic error in the loops will give a seg fault
Based on the data collected: The hypothesis was not entirely correct. The hypothesis was very vague as was the question posed. If The hypothesis could have been slightly more specific the experiment might have had a little more guidance.
The main cause of segmentation faults are logic errors but logic errors also lead to other types of problems within the program.
Today we covered a couple of new pieces of material in class. The first of which is a typedef which renames something to be more easily referenced in the code. The other was a union. The thing to remember about unions is that they are like an array but can have different data types within whereas an array can only have one data type. The union can be useful only if the things inside of it need not be used at the same time.
The other brief lesson was on struct which is similar to a union but different. A struct does not share memory space like a union but instead creates memory for each but you still need to allocate.
Today I caught up on some of the things I missed the previous week. One of these concepts was multifile and inheritance. We set up codes in different code sets and then linked them all together. This is multifile. It isn't terribly difficult but it does require some thinking especially if writing header files to be incuded in the different code blocks that will be used for inheritance. I think I mostly understand how it works but making sure I have defined everything is going to be my biggest challenge. Also making sure that I i define the header files properly and include them using the right syntax will also be something to keep an eye out for.
This day in class history we talked about cin, cout, and cerr. It became clear that to use cout would take a lot more syntax than using a printf statement. Conversely, it takes a little less to use a cin statement instead of a scanf statement. We also played around a little more with multifiles and gates. Gates are an interesting concept that I need to explore further in how to set them up properly.
Inheritance was the topic of the day. We focused mostly on perfecting it and understanding the concept behind it. I do understand it and I am fairly confident that the next topic of polymorphism will confound but not completely baffle with no ray of sunshine.
keywords
typedef: rename function in code aka alias union: a container that can contain more than one data type. it allocates memory to the largest data type within and only works with one data type at a time. can only be used when the things inside need not be used at the same time
#include <stdio.h> #include <stdlib.h> int main() { int i; union var{ int x; float f; }; typedef union var Uif; Uif value; value.x=0; for(i=0; i<24; i++) { value.x=value.x+rand()%51+1; } printf("total is %d\n", value.x); for(i=0; i<73; i++) { value.f=value.f+rand()%27+0.1; } printf(total is %f\n, value.f); } return(0); }
this program utilizes typedef and a union
equations, operations
the basic arithmetic functions learned in math class applied to bits and code
#include <stdio.h> int main() { int i=value=0; for(i=0; i<33; i++) { value=i+3 } return(0); }
This code increments the integer i by 3 and cycles through the loop until i=33 then exits
types, ranges, sizes
the basic deciding factors of how much memory needs to be allocated for a program
lab46:~/src/cprog$ $ ./range An unsigned char is 1 bytes The range of an unsigned char is 0 to 255 An unsigned char can store 256 unique values A signed char is 1 bytes The range of a signed char is -128 to 127 An unsigned short int is 2 bytes The range of an unsigned short int is 0 to 65535 An unsigned short int can store 65535 unique values A signed short int is 2 bytes The range of a signed short int is -32768 to 32767 An unsigned int is 4 bytes The range of an unsigned int is 0 to 255 An unsigned int can store 4294967295 unique values A signed int is 4 bytes The range of a signed int is 0 to -1 An unsigned long int is 8 bytes The range of an unsigned long int is 0 to 255 An unsigned long int can store 18446744073709551615 unique values A signed long int is 8 bytes The range of a signed long int is 1 to -2 An unsigned long long int is 8 bytes The range of an unsigned long long int is 0 to 255 An unsigned long long int can store 18446744073709551615 unique values A signed long long int is 8 bytes The range of a signed long long int is 1 to -2 lab46:~/src/cprog$
This is a printout of the results of project 0
return types, pass by value, address reference
contains smaller operations within a bigger operation
#include <stdio.h> #include <stdlib.h> int sum(int, int, int, int); //function prototype float avg(int, int, int, int); int numset(int, int, int, int); int main() { int a, b, c, d; a=b=c=d=0; printf("Enter first value: "); fscanf(stdin, "%d", &a); printf("Enter second value: "); fscanf(stdin, "%d", &b); printf("Enter third value: "); fscanf(stdin, "%d", &c); printf("Enter fourth value: "); fscanf(stdin, "%d", &d); fprintf(stdout, "the sum of %d, %d, %d, and %d is %d\n", a, b, c, d, sum(a,b,c,d)); fprintf(stdout, "the average of %d, %d, %d,and %d is %f\n, a,b,c,d, avg(a,b,c,d)); return(0); int sum(int n1, int n2, int n3, int n4) { int total=0; total=n1+n2+n3+n4 return(total); } float avg(int n1, int n2, int n3, int n4) { float avgerage=0 avgerage=(n1+n2+n3+n4)/4); return(avgerage); }
lab46:~src/cprog$ ./function1 Enter first value: 5 Enter second value: 7 Enter third value: 8 Enter fourth value: 9 the sum of 5,7,8, and 9 is 29 the average of 5,7,8, and 9 is 7.000000 lab46:~src/cprog$
This is the code and output of the program function1.c written in class
preprocessor, flags, assembly linker…
takes the code written in a text editor and makes it machine readable and executable
lab46:~/src/cprog$ gcc -o function1 function1.c lab46:~/src/cprog$
This shows that the code written in function1.c was successfully compiled to executable form in function1. There are flags and warnings and errors that can appear that state if there is a segmentation fault or a syntax error that will not allow the program to compile.
Block, Local, Global, File
the part of code in which identifier can be referenced.
From broadest to narrow: application, file, function, block
Taken from lrdev.com
if, case/switch
When there is a series of if/else statements in a code a case switch may be used
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
#include <stdio.h> main() int menu numb1, numb2, total; printf(" enter in two numbers-->"); scanf("%d, %d", &numb1, &numb2); printf("enter in choice\n") printf("1=addition\n"); printf("2=subtraction\n"); scanf("%d", &menu); switch(menu){ case 1: total=numb1+numb2; break; case 2: total=numb1-numb2; break; default: printf("Invalid option selected\n") } if(menu==1) { printf("%d plus %d is %d\n", numb1, numb2, total); } else { printf(%d minus %d is %d\n", numb1, numb2, total); } return(0); }
Example taken from gd.tuwien.ac.at/language/c/programming-bbrown/c_028htm
Declarations, Accessing Elements, Pointers to
basically the same as a union except it will allocate memory for each member but does not share memory
#include <stdio.h>
int main()
{
struct person{
char *name;
unsigned char age;
short int weight;
float gpa;
};
return(0);
}
This is the setup for a struct based on characteristics of a person
Distinguish and explain the difference between homogeneous and heterogeneous composite data types
Can the student correctly identify a homogeneous composite data type and a heterogenous composite data type?
Write a code for both a heterogeneous and homgeneous containers
<code> #include <stdio.h>
int main() {
struct time{
float sec;
char min;
int hour;
short int day;
};
long int century[20]
return(0);
}
This is not a complete view of the code but it does show the difference in how each of these types are set up. The struct allocated memory for each of the elements within and accessed them. There are many different data types within the struct. When trying to add different data types to the array century the compiler will not allow because it only a long int can go into century. The array is homogeneous and the struct is heterogeneous.
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.
Perform the following steps:
Whose existing experiment are you going to retest? Provide the URL, note the author, and restate their question.
Evaluate their resources and commentary. Answer the following questions:
State their experiment's hypothesis. Answer the following questions:
Follow the steps given to recreate the original experiment. Answer the following questions:
Publish the data you have gained from your performing of the experiment here.
Answer the following:
Answer the following:
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
Identification of chosen keyword (unless you update the section heading above).
Definition (in your own words) of the chosen keyword.
Demonstration of the chosen keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki code block, an example follows:
/* * Sample code block */ #include <stdio.h> int main() { return(0); }
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$
State the course objective
In your own words, define what that objective entails.
State the method you will use for measuring successful academic/intellectual achievement of this objective.
Follow your method and obtain a measurement. Document the results here.
Reflect upon your results of the measurement to ascertain your achievement of the particular course objective.
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.
Perform the following steps:
Whose existing experiment are you going to retest? Provide the URL, note the author, and restate their question.
Evaluate their resources and commentary. Answer the following questions:
State their experiment's hypothesis. Answer the following questions:
Follow the steps given to recreate the original experiment. Answer the following questions:
Publish the data you have gained from your performing of the experiment here.
Answer the following:
Answer the following: