syscall_example1.c created online with Bitbucket

Author: atulkumarpccs

KernelDrivers_March2011/syscall_example1.c

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+#include<errno.h>
+#include<asm/unistd.h>
+#include<unistd.h>
+#include<stdio.h>
+#include<stdlib.h>
+#include "syscallmacros.h"
+
+extern char **environ;
+
+_syscall3(ssize_t,write,int,fd,const void *,buf,size_t,count)
+
+_syscall3(long,open,const char *,filename,int,flags,int,mode)
+
+_syscall0(pid_t,getpid)
+
+
+int main()
+{
+    
+
+   int ret,ret1;
+
+   char str[1024];
+
+   ret = snprintf(str,sizeof(str), "the pid of the process is %d\n", getpid());
+  
+   ret1 = write(STDOUT_FILENO,str,ret+1);
+
+   if(ret1<0){ perror("error in write syscall"); exit(1);}
+
+   ret1 = getpid();
+   
+
+   if(ret1<0){ perror("error in open syscall"); exit(2);}
+
+   exit(0); 
+}