C -Take text as Parameter

Question

#include <stdio.h>
#include <string.h>

int contain( int argc, char* argv[]) 
{
int i;
int j;
int lenst1;
int lenst2;
int pos1;
int pos2;

if (lenst2>lenst1)
{
    printf("flase");
    return 0;
}
for (j=0; j<lenst1;j++)
{
    for (i=0; i<lenst2; i++)
    {
        if (st2[i]==st1[j])
        {
            pos1=j;
            pos2=i;
            while (pos2<lenst2)
            {
                pos2++;
                pos1++;
                if (st2[i]==st1[j])
                {

                }
                else
                {
                    printf("flase\n");
                    return 0;
                }
                printf("true\n");
                return 0;
            }
        }
    }
}
}

My goal is to write a program called "contains" that takes two text strings as arguments and prints "true" followed by a newline.

If the second string is entirely contained within the first, or "false" followed by a newline otherwise. I think my logic is correct. My question is how do I pass these two strings as parameters.

A good start would be to actually *have* two strings. Which you don't. And use *initialized* variables. Perhaps you [need to read a good beginners book](http://stackoverflow.com/questions/562303/the-definitive-c-book-guide-and-list)? — Some programmer dude, Feb 10 '17 at 05:23

score 0 · Answer 1 · answered Feb 10 '17 at 05:27

0

Initialise your variables in the main. If you want it as a parameter then write the logic in some other function and call it by passing the two strings as variables and define them in the main.

answered Feb 10 '17 at 05:27

Ria Sen

94
13

Scheff's Cat · Answer 2 · 2017-02-10T05:53:21.083

The two "standard" parameters of main are responsible for this.

argc ... number of command line arguments
argv ... array of strings with command line arguments.

Thereby, argv[0] provides the name of the program.

In your case:

#include <stdio.h> /* for printf, fprintf */
#include <string.h> /* for strlen */

int main(int argc, char **argv)
{
  char *str1, *str2;
  /* check for min. number of required args. */
  if (argc <= 2) {
    fprintf(stderr, "ERROR! At least one arg. missing!\n");
    return -1;
  }
  /* get args. */
  str1 = argv[1]; str2 = argv[2];
  /* (the strings are 0-terminated) */
  printf("argv[1]: '%s' (length: %d)\n", str1, strlen(str1));
  printf("argv[2]: '%s' (length: %d)\n", str2, strlen(str2));
  /* process data */
  /* done */
  return 0;
}

Compile and run:

$ gcc -o testArgs ./testArgs.c

$ ./testArgs
ERROR! At least one arg. missing!

$ ./testArgs Hello "Hello world"
argv[1]: 'Hello' (length: 5)
argv[2]: 'Hello world' (length: 11)

More info:

command line arguments: google c main argc argv
working with 0-terminated strings: google c strlen.

C -Take text as Parameter

2 Answers2