How do I pass options at the prompt.

First the code

Code:

---

[cdalten@localhost YAPP]$ more main.c
#include <stdio.h>
#include <stdlib.h>

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

  conference(&argc, &argv);

  /*cleanup();*/
  exit(EXIT_SUCCESS);
}
[cdalten@localhost YAPP]$

---

Code:

---

[cdalten@localhost YAPP]$ more driver.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static char buf[BUFSIZ];

int strip_line(char line[]) {
  int n;

  for (n = strlen(line)-1; n >= 0; n--)
    if (line[n] != ' ' && line[n] != '\t')
      break;
  line[n+1] = '\0';
  return n;
}

void conference_prompt(void) {
  fputs("Type Help for more information\n", stdout);

  do {
    strip_line(buf);
    fputs("OK:", stdout);
    fflush(stdout);
  } while (fgets(buf, BUFSIZ, stdin) != NULL);
}


void conference(int *argc, char *argv[]) {
  if (*argc == 1) {
    conference_prompt();
  }
}

[cdalten@localhost YAPP]$

---

Quote:

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[cdalten@localhost YAPP]$ gcc main.c driver.c -o yapp
[cdalten@localhost YAPP]$ ./yapp
Type Help for more information
OK:

---

What I want to do is for a user to get a help menu when they type 'h' or 'help' at the 'OK:' prompt. I looked at getopt() but that only seems to work with command line args. And the switch statement doesn't seem to want to work when it see something like 'help'. Ideas?

You do it the same way for any function.

Code:

---

int foo(int argc, char **argv)
{
        printf("argc = %i, argv[0] = %s\n", argc, argv[0]);
        return 0;
}
int main(int argc, char **argv)
{
        return foo(argc, argv);
}

---

But I don't want 'h' passed at the command line. Ie, I don't want

Quote:

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./yapp h

---

I just want 'h' passed a the 'OK:' prompt.

Ah, I see. I gotta bad habit about not reading the whole sentence. . .

Code:

---

char *cmds[] = { "H", "HELP", "ETC", "\0" };
int match(const char *which)
{
        int i;
        for (i = 0; cmds[i][0] != '\0'; i++){
                if (!strcmp(cmds[i], upcase(which)){
                        break;
                }
        }
        if (cmds[i][0] != '\0'){
                return -1;
        }
        return i;
}

---

You'll have to write upcase.

[edit] switch(match(userinput)){[/edit]

The GNU C Reference Manual

Pretty much a "must read" if you are on linux.

[edit] okay, I just looked over your first post and you know how to use fgets. Maybe you need to read about strcmp()...also, there is a strncmp() which will work with the first n characters in a string, alleviating the need for your "strip line" function*... kind of strange you are having a problem with this IMO[/edit]

* which you should not use strlen in a for loop like that, it's a waste to do it over and over. Just set a variable to the strlen before the loop.

You might want to read the manpage for getopt as that will do you option handling for you. Saves reinventing the wheel.

Oops, I misread your post >_<

Looks like we hit 3 for 3 misreading your post Overworked_Phd. Maybe it is time for:

How To Ask Questions The Smart Way*

Anyway, my other thought was that you could use a restricted scanf template to read the input and lose the "strip_line function":

Code:

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scanf("%32[a-zA-Z]",buf);

---

I used 32 in place of BUFSIZE since you cannot use a define in the scanf template. This will read only contiguous characters in the set a-z and A-Z (no spaces, tabs, newlines, etc. Then use strcmp().

*how did you not do this? Well, you said you were having a problem reading user input, which is not true. A common error is the desire is to post code demonstrating what you have done correctly, then tacking a vague question on, instead of focussing on what you are having a problem with.