Get Parameters with C

Get parameters

• interactive approach:

<source lang="c">

1. include "stdio.h"

int main() {

 char * c;
 int i = 0;
 double d = 0.0;

 printf("Enter a word\n");
 scanf("%s",c);
 printf("Enter an integer\n");
 scanf("%d",&i);
 printf("Enter a double\n");
 scanf("%lf",&d);
 printf("You gave : %s %d %lf",c,i,d);
 printf("\n");

 return 0;

} </source>

• from the command line:

<source lang="c">

1. include "stdio.h"

int main(int argc, char* argv[]) {

 if(argc != 4)
   {
     printf("\tUsage:\t");
     printf("%s",argv[0]);
     printf(" <char> <integer> <double>\n");
   }
 else
   {
     char * c =  argv[1];
     int i = atoi(argv[2]);
     double d = atof(argv[3]);
     printf("You gave : %s %d %lf",c,i,d);
     printf("\n");
   }
 return 0;

} </source>

• from a file, considering that you have a defined routine process() to do the job

<source lang="c">

1. include "stdio.h"

void process(FILE * file) { ...fscanf(...)... }

int main(int argc, char* argv[]) {

 if(argc != 2)
   {
     printf("\tUsage:\t");
     printf("%s",argv[0]);
     printf(" <inputfile>\n");
   }
 else
   {
     char * filename =  argv[1];
     FILE * input = fopen(filename,'r');
     process(input);
     fclose(filename);
   }
 return 0;

} </source>