Conditional branching - which 'if ( )' and 'else ( )' afford us - has a step-brother called "the SWITCH / CASE' block. Here we look at that interesting feature of 'C'. We also touch on using 'man' pages as an immediate language / function reference.
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why not try using the MAN page to find out what 'strstr()' does, and how to use it. In the terminal window, enter "man strstr" ('q' exits MAN). Also try a MAN query for 'strcat()' using "man strcat"... |
/* pgm15 source */
#include <stdio.h>
#include <string.h> // we use 'strstr()' in this program
#define STRINGLEN 375
void load_up_string(char *);
int main(int argc, char *argv[]) {
char line[STRINGLEN];
memset(line, '\0', STRINGLEN); // null-out the entire string
load_up_string(&line[0]); // now fill the string with words
switch (argc) {
case 1 : { // = NO command line parameters, just show string
printf("\n%s\n\n", line);
printf("The 'line[]' array is %ld characters large.\n\n", strlen(line));
printf("Now, run program again with something to search for.\n");
break;
}
case 2 : { // = ONE command line parameter, search for it
if (strstr(line, argv[1]) == NULL)
printf("\nAwww.... didn't find %s. No cookie for user. Try again.\n", argv[1]);
else
printf("\nBingo!! \"%s\" was found. We'll send you $3.00!\n", argv[1]);
break;
}
default : { // user gave > 1 command line parameter
printf("\nPlease run this program with 0 or 1 command line items.\n");
break;
}
}
printf("\n");
return(0);
}
void load_up_string(char *line) {
strcat(line, "When in the course of human events, it becomes necessary ");
strcat(line, "to decide upon a particular food or drink to consume in the ");
strcat(line, "presence of others (either friend or foe), one must take into ");
strcat(line, "account: Why, Where, When, Who, Which, and Monkey. ");
strcat(line, "A doctor a day keeps the apple away. A nine in time saves ");
strcat(line, "some number of stitches. You can tune a piano but you ");
strcat(line, "can't tuna fish.");
}