Sunil Bhagwat

 ********************************* Commands On LINUX******************************************** 1) vi - 'vi ' is the editor of LINUX Command Prompt.            vi Filename.c 2) gedit - 'gedit' is also the editor of LINUX or Ubuntu Command Prompt.               gedit Filename.c in this command gedit editor open in new window but our terminal is busy for all over process we will terminate it. To solve this problem using following command,                     gedit Filename.c & 3) cp - 'cp' command is use to copy one file to another file.             cp SourceFileName.c DestinationFileName.c 4) rm - 'rm' command is use to remove file.             rm FileName.c 5) mv - 'mv' command is use to move one file to another file.             mv  SourceFileName.c DestinationFileName.c 6) touch - 'touch' command is use to create new empty file or change file timestamps.             touch fileName.c 7) cat

                                                      Signal Handling 1) Signal handling is one of the way of Inter Process Communication in which one process can notify the other process by sending the signal but in case of signal handling we can not send actual data to the other process. 2) In case of signal handling signal is pass through the operating system and operating system will forward that signal to the receiver process. 3) Every signal is identified by unique number which is called as signal number. 4) To perform signal handling we have to use two function as : i) signal( ) and ii) kill( ).      i) signal( ) function is use to decide the action which is to send the signal to any of the process whose pid should be pass as parameter.     ii) kill( ) function is use to send the signal to the any process. 5) By using signal handling we can send signal to any process which can be related or not. --------------------------------------------------------------------

Message Queue:- 1) This is the another way of Inter Process Communication. In which one process can communicate with other process by sending the message. 2) In this concept we have to send message to the operating system and that message is accepted by the operating system then that message gets inserted into a message queue by the operating system. 3) If receiver process is running then that process request to get the message to the operating system then depend on the id of that process operating system receive that message from the message queue and that message gets displayed to the receiver process. 4) The internal mechanism of message queue and shared memory is almost similar. ------------------------------------------------------------------------------------------------------------ Steps followed by the message sender. 1) Include header file as msg.h. 2) Decide the structure which is use to receive the message. 3) Decide the key which is use for communication.

Inter Process Communication in UNIX    1)       System V is universally accepted and most successful version of UNIX Operating System. This version of UNIX provides multiple things to other Operating System such as i)                     TCP/IP Protocol suite. ii)                    Multiple IPC Techniques. iii)                  Concept of Pipe. iv)                  Concept of Socket Programming etc.    2)       We can perform Inter Process Communication by using different techniques such as i)                     Shared Memory. ii)                    Message Queue. iii)                  Pipe. iv)                  Memory Map Files. v)                   FIFO (Queue).    3)       Each an every IPC techniques has different perspective depend on the data should be send and the data which can be received by the other processes. 1)       Shared Memory :- i)                     Shared memory is the fastest way of process communication. ii)