Awesome C Programming Language

ANSI C | C99 | C11 | C17 | C23

   

📖 Contents

• Pointers
• Dynamic Memory Management
• Structures
• Unions
• Enumarations
• Bitwise Operations
• String Library
• Signal Handling
• C Process Control
• My Other Awesome Lists
• Contributing
• Contributors

Declarations & Definitions

• Function Declarations: A function can be declared several times in a program, but all declarations for a given function must be compatible;
  • the return type is the same
  • the parameters have the same type.

  float square(float x);

Function declarations do not allocate storage.

• Function Definitions:

  float square(float x) {
      return x*x;
  }

Type Conversions

Arrays

Scope & Name Lookup

🔼 Back to top

Pointers

int ival;
double darray[5];

• ival has type int; we say &ival is a "pointer to int."
• darray has type double[5]; we say &darray is a "pointer to an array of five doubles."
• darray[3] has type double; we say &darray[3] is a "pointer to double."

You can find more details at the link

🔼 Back to top

Dynamic Memory Management

malloc

#include <stdlib.h>
void *malloc(size_t size);

int ptrIArray[10];

malloc() takes a single argument (the amount of memory to allocate in bytes).

calloc

#include <stdlib.h>
void *calloc(size_t nelem, size_t elsize);

Allocates memory for an array of num objects of size and initializes all bytes in the allocated storage to zero.

realloc

realloc() is used to resize previously allocated memory (from malloc(), calloc(), or a previous realloc() call). It allows you to:

• increase array size
• shrink array size
• avoid losing existing data
• avoid manually copying the old array

#include <stdlib.h>
void *realloc(void *ptr, size_t size);

• If ptr is a null pointer, realloc() shall be equivalent to malloc() for the specified size.

free

#include <stdlib.h>
void free(void *ptr);

Releases the specified block of memory back to the system.

You can find more details at the link

🔼 Back to top

Structures

A struct in C is a user-defined data type grouped together under one name. Its members can be of different data types (unlike arrays).

struct Person {
    char name[50];
    int age;
    float height;
};

int main() {
    struct Person p1;

    // Assign values
    strcpy(p1.name, "Alex");
    p1.age = 25;
    p1.height = 1.75f;

    printf("Name:\t%s\n", p1.name);
    printf("Age:\t%d\n", p1.age);
    printf("Height:\t%.2f\n", p1.height);

    return 0;
}

🔼 Back to top

Unions

A union is like a struct, but all members share the same memory location. This means:

• A union can store only one member at a time
• Size of union = size of its largest member
• Writing to one member affects all others (because they overlap in memory)

union Data {
    int ival;
    float fval;
    char cval;
};

int main() {
    union Data Dval;

    Dval.ival = 26;
    printf("Dval.ival = %d\n", Dval.ival);

    Dval.fval = 3.14;
    printf("Dval.fval = %.2f\n", Dval.fval);

    Dval.cval = 'A';
    printf("Dval.cval = %c\n", Dval.cval);

    return 0;
}

🔼 Back to top

Enumarations

An enumeration (enum) is a user-defined data type that lets you assign names to integer constants.

• Basic Enum Example

  enum Day {
      MONDAY,
      TUESDAY,
      WEDNESDAY,
      THURSDAY,
      FRIDAY,
      SATURDAY,
      SUNDAY
  };
  
  int main() {
      enum Day today = SATURDAY;
      printf("Today is day number: %d\n", today);
      return 0;
  }

You can find more details at the link

Bitwise Operations

Strings library

String Manipulation

Byte string	Wide string	Description
strcpy	wcscpy	Copies one string to another
strncpy	wcsncpy	Writes exactly n bytes/characters, copying from source or adding nulls
strcat	wcscat	Appends one string to another
strncat	wcsncat	Appends no more than n bytes/characters from one string to another
strxfrm	wcsxfrm	Transforms a string according to the current locale

String Examination

You can find more details at the link

Miscellaneous

🔼 Back to top

Signal Handling

Signal Number	Name	Meaning	Catchable?
1	SIGHUP	Hangup detected	✔ Yes
2	SIGINT	Interrupt (Ctrl+C)	✔ Yes
3	SIGQUIT	Quit (Ctrl+)	✔ Yes
4	SIGILL	Illegal instruction	✔ Yes
5	SIGTRAP	Trace/breakpoint trap	✔ Yes
6	SIGABRT	Abort	✔ Yes
7	SIGBUS	Bus error	✔ Yes
8	SIGFPE	Floating‑point exception	✔ Yes
9	SIGKILL	Kill immediately	❌ No
10	SIGUSR1	User-defined signal 1	✔ Yes
11	SIGSEGV	Segmentation fault	✔ Yes
12	SIGUSR2	User-defined signal 2	✔ Yes
13	SIGPIPE	Broken pipe	✔ Yes
14	SIGALRM	Alarm clock	✔ Yes
15	SIGTERM	Termination request	✔ Yes
16	SIGSTKFLT	Stack fault (Linux specific)	✔ Yes
17	SIGCHLD	Child stopped/terminated	✔ Yes
18	SIGCONT	Continue executing	✔ Yes
19	SIGSTOP	Stop the process	❌ No
20	SIGTSTP	Stop (Ctrl+Z)	✔ Yes
21	SIGTTIN	Background read from TTY	✔ Yes
22	SIGTTOU	Background write to TTY	✔ Yes
23	SIGURG	Urgent condition on socket	✔ Yes
24	SIGXCPU	CPU time limit exceeded	✔ Yes
25	SIGXFSZ	File size limit exceeded	✔ Yes
26	SIGVTALRM	Virtual alarm clock	✔ Yes
27	SIGPROF	Profiling timer expired	✔ Yes
28	SIGWINCH	Window size change	✔ Yes
29	SIGIO	I/O now possible	✔ Yes
30	SIGPWR	Power failure	✔ Yes
31	SIGSYS	Bad system call	✔ Yes

You can find more details at the link

🔼 Back to top

C Process Control

🔼 Back to top

Severals

• cJSON - Ultralightweight JSON parser in ANSI C.
• Doxygen - Doxygen is a widely-used documentation generator tool in software development.

🔼 Back to top

Compiler/Debugger

• MSVC & GCC & Clang - installation step of MSVC/GCC/Clang compiler in Windows
• GCC & Clang - installation step of GCC/Clang compiler in Linux
• OnlineGDB - Online compiler and debugger for C/C++

My Other Awesome Lists

You can access the my other awesome lists here

Contributing

Contributions of any kind welcome, just follow the guidelines!

Contributors

Thanks goes to these contributors!

License

🔼 Back to top