47 lines
1.6 KiB
C
47 lines
1.6 KiB
C
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/*
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Written By: Prawar Poudel
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execvp runs a program that you pass as argument
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Please study about the execvp function before going to run this program
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After you understand the things, please run and watch them
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Please make sure that execvp has the right executable provided
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*/
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#include <unistd.h>
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#include <string.h>
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#include <stdio.h>
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#include <sys/wait.h>
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int main()
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{
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char myArgument[100];
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//you can change the content of myArgument using any user typed input using gets()
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strcpy(myArgument,"date");
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//execvp expects the arguments to be provided as char[][]
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//so please make sure you understand strtok before coming here
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//we will use strtok() to break the sequence of command and argument in myArgument to convert to char[][]
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char* myBrokenArgs[10]; //this will hold the values after we tokenize
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printf("Starting tokenization...\n");
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myBrokenArgs[0] = strtok(myArgument," ");
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int counter = 0;
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while(myBrokenArgs[counter]!=NULL)
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{
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counter+=1;
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myBrokenArgs[counter] = strtok(NULL," ");
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}
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myBrokenArgs[counter] = NULL;
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printf("\ttokenization complete....\n\nNow executing using execvp\n");
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printf("Following will be the output of execvp\n");
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printf("=======================================\n");
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int id;
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//I will spawn a child that will run my execvp command
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if((id=fork())==0)
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execvp(myBrokenArgs[0],myBrokenArgs);
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else if(id<0)
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printf("Failed to make child...\n");
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else
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{
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//parent shall wait until the child is killed
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wait(0);
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printf("=======================================\n"); printf("Completed execution\n");
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}
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return 0;
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}
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