System calls –
• System call provides an interface made available by operating system.
• System call provides the interface between processes an operating system.
• These calls are generally available as assembly level instruction.
• Some system may allow system call should be directly form of high level language like – c, c++.
• System call can be grouped into five major categories –
1. Process control
2. File management
3. Device management
4. Information maintenance
5. Communication
1. Process control –
• Start, end
• Load, execute
• Create process, terminate process
• Get process attribute, set process attribute
• Wait for time
• Allocate and free memory
2. File management –
• Create file, delete file
• Open, close
• Read, write
• Get file attribute, set file attribute
3. Device management –
• Request device, release device
• Read, write
• Get device attribute, set device attribute
• Logically attach/deattach device
4. Information maintenance –
• Get/set time or date
• Get/set system data
• Get process, file, device attributes
• Set process, file, device attributes
5. Communication –
• Create and delete communication device
• Send and receive message
• Transfer status information
• Attach or detach remote devices
Example of windows and Unix
• System call provides an interface made available by operating system.
• System call provides the interface between processes an operating system.
• These calls are generally available as assembly level instruction.
• Some system may allow system call should be directly form of high level language like – c, c++.
• System call can be grouped into five major categories –
1. Process control
2. File management
3. Device management
4. Information maintenance
5. Communication
1. Process control –
• Start, end
• Load, execute
• Create process, terminate process
• Get process attribute, set process attribute
• Wait for time
• Allocate and free memory
2. File management –
• Create file, delete file
• Open, close
• Read, write
• Get file attribute, set file attribute
3. Device management –
• Request device, release device
• Read, write
• Get device attribute, set device attribute
• Logically attach/deattach device
4. Information maintenance –
• Get/set time or date
• Get/set system data
• Get process, file, device attributes
• Set process, file, device attributes
5. Communication –
• Create and delete communication device
• Send and receive message
• Transfer status information
• Attach or detach remote devices
Example of windows and Unix
Example – consider a simple program to read data from one file
and to copy them to another file.