Presentation about C language done at Master on Free Software 2009 Edition

1. C language
Juan A. Suárez Romero
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2. List of topics
● History
● Control structures
● Data types
● Operators
● Preprocessor
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3. History
● Developed by Dennis Ritchie
● Goal: port a SO from PDP-7 to PDP-8
● K&R C
● Ansi C (C89/C90 - C99)
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4. Example
#include <stdio.h>
int main(int argc, char *argv[])
{
printf (“Hello, world!n”);
return 0;
}
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5. Control structures
while (condition) statement_set;
do statement_set while (condition)
for (initial_cond, final_cond, change_action)
statement_set
if (condition) st_set else st_set2;
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6. Data Types
● Simple types
– char, int, float, double
– signed/unsigned
● Complex types
– arrays, structures, unions
– strings (arrays of char ended in NULL)
● 'Special' types
– Pointers
– Void Master on Free Software

7. Data types
#include <stdio.h>
int main(int argc, char *argv[])
{
char letter;
double pi;
float height;
int first_prime_numbers[30];
}
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8. Data types
struct email {
int sent_date;
char *sender;
char *subject;
char *content;
};
struct email *myemail;
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9. Arrays / pointers
● Array is actually a pointer to a chunk of
memory
● Uses of * and &
char *a;
char b;
*a?? &b?? (a = &b)?? (b = *a)??
● Pointer arithmetic: a[3] == *(a+3)
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10. Operators
● Arithmetic (+, -, *, /, %)
● Logical (&&, ||, ==, !=, >=, <=)
● Increment / Decrement
● Size of a type
● Self assignment (+=, -=, ...)
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11. Preprocessor
● Definitions
– #define, #undef
● Conditional compiling
– #if, #ifdef, #ifndef, #else, #endif
● Include other files
– #include
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12. Functions
int multiply (int n1, int n2);
int multiply (int n1, int n2)
{
return n1*n2;
}
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13. References
●
The C Programming Language (2nd
edition)
– Brian W. Kernighan
– Dennis M. Ritchie
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