Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!timbuk!shamash!bls
From: bls@u02.svl.cdc.com (Brian Scearce)
Newsgroups: comp.lang.c
Subject: Re: strings as functions
Keywords: strings pointers functions
Message-ID: <29668@shamash.cdc.com>
Date: 7 Jan 91 22:21:47 GMT
References: <mpapp.663214690@godzilla>
Sender: usenet@shamash.cdc.com
Lines: 49

mpapp@ (Mike Papper) writes:
>Is there a way to use a string value as the name of a function?

It depends on what you mean.  If, at compile time, you can make up
a table, then it is pretty easy:

#include <stdio.h>
#define MAXLEN 100

void first(), second(), third(), last();

struct mapping {
  char *name;
  void (*func)();
};

main()
{
  void first(), second(), third(), last();
  static struct mapping list[] = 
    { "first", first,
      "second", second,
      "third", third,
      "last", last,
      NULL, NULL
    };

  char buf[MAXLEN];
  int i;

  while (fgets(buf, MAXLEN, stdin) != NULL) {
    buf[strlen(buf)-1] = 0; /* Get rid of newline */
    for (i = 0; list[i].name; i++)
      if (strcmp(list[i].name, buf) == 0)
        (*list[i].func)();
  }
}

void first() { printf("First function\n"); }
void second() { printf("Second function\n"); }
void third() { printf("Third function\n"); }
void last() { printf("Last function\n"); }

--
     Brian Scearce (bls@robin.svl.cdc.com  -or-  robin!bls@shamash.cdc.com)
        "How do you explain the vast discrepancy between your testimony
         and my client's?" "He has perjured himself." "Objection!" "I am
         under oath.  I was there.  He *is* lying."
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