| Line 2: | Line 2: | ||
| − | + | Lecture 3 | |
| + | |||
| + | Lecture 3 – 1/17/2012 | ||
| + | |||
| + | In class quiz – Know 3 or more classmates, their names, hometown, interests, career goals (submitted at the end of class) | ||
| + | |||
| + | Reminder | ||
| + | • Exercise 1 due this coming Friday (January 20th) | ||
| + | • Write Programs in EE206 | ||
| + | • Check blackboard everyday | ||
| + | • Submit your signature on the class policy sheet given the first day of class | ||
| + | • Office Hours: | ||
| + | o Tuesday and Friday after class in MSEE222, open door policy. You can discuss any topic. | ||
| + | |||
| + | Today’s Programs | ||
| + | • Review of simple C programs | ||
| + | • Programming in Linux | ||
| + | • Maze files and rules | ||
| + | • Arc and argv | ||
| + | • Program to read characters in a file | ||
| + | • Function calls | ||
| + | • Practice how to write a program that can find 26 English characters and tell which ones appear the most often (ignore cases) | ||
| + | • Challenge: Write a program that can generate valid mazes | ||
| + | |||
| + | In Linux… | ||
| + | • mkdir → makes a new directory (folder) | ||
| + | o EX: mkdir ECE264 | ||
| + | • ls → lists the files in the directory | ||
| + | o EX: ls | ||
| + | • cd → changes the directory | ||
| + | o EX: cd Exercises | ||
| + | • File → determines what type of file you are dealing with | ||
| + | o EX: file prog1 (returns a ‘.c’ file type) | ||
| + | • emacs/vi filename.c → creates a file and puts it into a text editor of choice | ||
| + | |||
| + | NOTE: Make sure never to have space in file name | ||
| + | |||
| + | • What is used to compile programs? | ||
| + | o Linux: gcc prog1.c -o prog1 | ||
| + | o Translation: Compiler Human Readable Name of Output file Machine Readable | ||
| + | |||
| + | o Linux: ./(no space)ex1 data | ||
| + | o Translation: Run Machine Readable and use a text file called data | ||
| + | |||
| + | Example 1: | ||
| + | |||
| + | a =1 | ||
| + | b=2 | ||
| + | if(a>b) | ||
| + | printf(“…”); | ||
| + | a = 5 | ||
| + | |||
| + | What is the value of ‘a’ here? a = 5. | ||
| + | |||
| + | • In the statement above, it doesn’t matter what is inside the if statement because ‘a’ is later redefined to be a OUTSIDE the if statement | ||
| + | • Always remember to use brackets with all logic statements | ||
| + | • No “end” in C (as in MATLAB if statements) | ||
| + | |||
| + | Indexing | ||
| + | • In C, index always begins with 0 | ||
| + | |||
| + | int arr[6]; | ||
| + | |||
| + | for( c = 0; c < 6; c++) | ||
| + | { | ||
| + | c will be 0,1,2,3,4,5 | ||
| + | } | ||
| + | |||
| + | It is wrong to do the following: | ||
| + | |||
| + | int arr[6]; | ||
| + | |||
| + | for( c = 0; c <= 6; c++) | ||
| + | { | ||
| + | c will be 0,1,2,3,4,5,6 ERROR: INDEX OUT OF RANGE | ||
| + | } | ||
| + | |||
| + | Inputting a string | ||
| + | • scanf(“%s”, str); | ||
| + | • printf(“%s”, str); | ||
| + | |||
| + | Maze program: | ||
| + | • Each wall is one layer thick | ||
| + | • Always one exit, one start | ||
| + | • Always one solution | ||
| + | • Pathways are on * in length | ||
| + | |||
| + | argc and argv | ||
| + | • Same as for function arguments, | ||
| + | |||
| + | int add( int a , int b) | ||
| + | |||
| + | • But instead, | ||
| + | |||
| + | Int main ( int argc , char *argv[] ) | ||
| + | |||
| + | (# of arguments, array of each argument) | ||
| + | |||
| + | argv element# | ||
| + | |||
| + | 0 . / a r g s \0 (What is stored in row 0) | ||
| + | |||
| + | 1 d a t a \0 (What is stored in row 1) | ||
| + | |||
| + | .... | ||
| + | |||
| + | |||
| + | • The first argument is always the name of the command | ||
| + | • Several spaces count only as 1 space separating the arguments | ||
| + | |||
[[Category:ECE264Spring2012Yung-Hsiang Lu]] | [[Category:ECE264Spring2012Yung-Hsiang Lu]] | ||
Revision as of 11:12, 22 January 2012
Rhea Section for ECE 264 Professor Yung-Hsiang Lu, Spring 2012
Lecture 3
Lecture 3 – 1/17/2012
In class quiz – Know 3 or more classmates, their names, hometown, interests, career goals (submitted at the end of class)
Reminder • Exercise 1 due this coming Friday (January 20th) • Write Programs in EE206 • Check blackboard everyday • Submit your signature on the class policy sheet given the first day of class • Office Hours: o Tuesday and Friday after class in MSEE222, open door policy. You can discuss any topic.
Today’s Programs • Review of simple C programs • Programming in Linux • Maze files and rules • Arc and argv • Program to read characters in a file • Function calls • Practice how to write a program that can find 26 English characters and tell which ones appear the most often (ignore cases) • Challenge: Write a program that can generate valid mazes
In Linux… • mkdir → makes a new directory (folder) o EX: mkdir ECE264 • ls → lists the files in the directory o EX: ls • cd → changes the directory o EX: cd Exercises • File → determines what type of file you are dealing with o EX: file prog1 (returns a ‘.c’ file type) • emacs/vi filename.c → creates a file and puts it into a text editor of choice
NOTE: Make sure never to have space in file name
• What is used to compile programs? o Linux: gcc prog1.c -o prog1 o Translation: Compiler Human Readable Name of Output file Machine Readable
o Linux: ./(no space)ex1 data o Translation: Run Machine Readable and use a text file called data
Example 1:
a =1 b=2 if(a>b) printf(“…”); a = 5
What is the value of ‘a’ here? a = 5.
• In the statement above, it doesn’t matter what is inside the if statement because ‘a’ is later redefined to be a OUTSIDE the if statement • Always remember to use brackets with all logic statements • No “end” in C (as in MATLAB if statements)
Indexing • In C, index always begins with 0
int arr[6];
for( c = 0; c < 6; c++) { c will be 0,1,2,3,4,5 }
It is wrong to do the following:
int arr[6];
for( c = 0; c <= 6; c++) { c will be 0,1,2,3,4,5,6 ERROR: INDEX OUT OF RANGE }
Inputting a string • scanf(“%s”, str); • printf(“%s”, str);
Maze program: • Each wall is one layer thick • Always one exit, one start • Always one solution • Pathways are on * in length
argc and argv • Same as for function arguments,
int add( int a , int b)
• But instead,
Int main ( int argc , char *argv[] )
(# of arguments, array of each argument)
argv element#
0 . / a r g s \0 (What is stored in row 0)
1 d a t a \0 (What is stored in row 1)
....
• The first argument is always the name of the command
• Several spaces count only as 1 space separating the arguments
