TB10.1 Example Applications: examples/PIPS/posixsignals/sigtermSignal/src/sigtermSignal.c Source File

00001 // sigtermSignal.c
-00002 //
-00003 // Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
-00004 // All rights reserved.
-00005 // This component and the accompanying materials are made available
-00006 // under the terms of "Eclipse Public License v1.0"
-00007 // which accompanies this distribution, and is available
-00008 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
-00009 //
-00010 // Initial Contributors:
-00011 // Nokia Corporation - initial contribution.
-00012 //
-00013 // Contributors:
-00014 //
-00015 // Description: The source code file for sigtermSignal.
-00016 //
-00017 
-00018 #include <stdio.h>
-00019 #include <stdlib.h>
-00020 #include <unistd.h>
-00021 #include <sys/types.h>
-00022 #include <signal.h>
-00023 #include <e32def.h>
-00024 #include <time.h>
-00025 
-00026 
-00027 FILE *gfp = NULL;
-00028 char *testfile = "C:\\testfile.txt";
-00029 
-00033 void PressKey()
-00034     {
-00035     int ch;
-00036     printf("Press 'e'+Enter to exit\n");
-00037     while((ch=getchar())!= 'e')
-00038         {
-00039         if(ch == '\n')
-00040             continue;
-00041         else
-00042             printf("wrong option selected, please try again!!!\n");
-00043         }
-00044     }
-00051 void SIGTERM_handler(int signum)
-00052     {
-00053     if(signum == SIGTERM)
-00054         {
-00055         if(gfp != NULL)
-00056             {
-00057             printf("Received the SIGTERM signal from the raiseSignal process\n");
-00058             fclose(gfp);
-00059             remove(testfile);
-00060             gfp = NULL;
-00061             printf("The open file descriptor was closed\n");
-00062             PressKey();
-00063             exit (0);
-00064             }
-00065         }
-00066     }
-00067 
-00077 int main()
-00078     {
-00079     char input[11];   
-00080     int count = 0,num;
-00081     int ch,ret;
-00082     pid_t usrProcsID;
-00083     const int delay = 4;                                    //Time delay of 4 sec provided.
-00084     const int size = 50;                                    //No.of characters allowed in the filename.
-00085     const int index = 3;                                    //No.of elements in the array.
-00086     
-00087     char *usrProcess = "Z:\\sys\\bin\\raisesignal.exe";    //Filename of process used for raising SIGTERM signal.
-00088     char **argv = (char**)malloc(index*sizeof(char*));      //Variable holding values to be passed on to the raiseSignal process. 
-00089     argv[0] = (char*)malloc(size*sizeof(char));
-00090     argv[1] = (char*)malloc(index*sizeof(char));
-00091     argv[2] = NULL;
-00092 
-00093     
-00094     strcpy(argv[0], "z:\\sys\\bin\\raisesignal.exe");       //argv[0] holding name of the child process.
-00095     sprintf(argv[1],"%d",getpid());                         //argv[1] holding parent pid.
-00096 
-00097     printf("*****************************************************************************************\n");
-00098     printf("* Welcome to the demonstration of a graceful process termination using a SIGTERM signal *\n");
-00099     printf("*****************************************************************************************\n");
-00100     
-00101     printf("* This example shows how a SIGTERM signal can be used to gracefully terminate a process.\n");
-00102     printf("* The example first creates a process called sigtermSignal, assigns a custom handler\nfor the SIGTERM signal, opens a file and gets names from the user to be written in to it.\n");
-00103     printf("* It then simultaneously spawns a raiseSignal process and starts reading from the file.\n");
-00104     printf("* The raiseSignal process sends a SIGTERM signal to the sigtermSignal process.\n");
-00105     printf("* On receiving the SIGTERM signal, the sigtermSignal process closes all the \nopen file descriptors and prepares to exit.\n");
-00106     
-00107     printf("\nPress the Enter key to continue\n");
-00108     getchar();
-00109 
-00110     signal(SIGTERM, SIGTERM_handler);
-00111     printf("************ In the sigtermSignal process ************\n");
-00112     printf("Enter the number of names you want to enter (e.g. 8) :\n");
-00113     scanf("%d", &count);
-00114     gfp=fopen(testfile, "w+");   //Opening the file for read and write.
-00115     if(gfp != NULL)
-00116         {
-00117         printf("File open sucessful\n");
-00118         }
-00119     else
-00120         {
-00121         printf("File open failed\n");
-00122         }
-00123     for(num=1; num<=count; num++)
-00124         {
-00125         printf("Name (%d)=", num);
-00126         scanf("%s", input);
-00127         fprintf(gfp, "%s\n", input);
-00128         }
-00129     
-00130     printf("Press the Enter key to spawn the raiseSignal process\n");
-00131     getchar();
-00132     getchar();
-00133     //Spawning raiseSignal process to accept user input.
-00134     ret = posix_spawn(&usrProcsID,usrProcess,NULL,NULL,argv,(char**)NULL);
-00135     if(ret != 0)     
-00136         {         
-00137         printf("\n*** failure posix_spawn ***\n");        
-00138         return EXIT_FAILURE;     
-00139         }
-00140      rewind(gfp);
-00141      printf("Starting to read from the file\n");
-00142      for(num=1; num<=count; num++)
-00143          {
-00144          sleep (delay);       
-00145          printf("Name (%d)=", num);
-00146          while((ch=(fgetc(gfp))) != '\n')
-00147                   {
-00148                   putchar(ch);
-00149                   }
-00150          printf("\n");
-00151          
-00152          }
-00153     if(!fclose(gfp))
-00154         {
-00155         remove(testfile);
-00156         gfp = NULL;
-00157         printf("File closed successfully\n");
-00158         }
-00159     else
-00160         {
-00161         printf("File close failed\n");
-00162         }
-00163   
-00164     PressKey();
-00165     return EXIT_SUCCESS;
-00166     }
-