Can anyone find a system on which this doesn't work?

[rf at wu1.UUCP]

Does anyone know of any system on which the acat() routine in
the program test.c (attached) does not work?  Acat is part of a
string management package -- an allocating concatenate routine.
It takes up to 10 strings, allocates storage for their
concatenation and concatenates them.

The output of test.c is given.  Test.c will end with the error
message "test: More than 10 strings in acat()".


				Randolph Fritz
UUCPnet:			{ihnp4,decvax}!philabs!wu1!rf

"Rust and moth are the only true Critics; . . ."
				-- "The True Critics", Paul Edwin Zimmer


----------------- output of test.c

1
122
122333
1223334444
122333444455555
122333444455555666666
1223334444555556666667777777
122333444455555666666777777788888888
122333444455555666666777777788888888999999999
----------------- test.c

#include <stdio.h>

typedef int VOID;
typedef unsigned int COUNT;
typedef char TEXT;
typedef int BOOL;
#define EOS	'\0'		/* End-of-string */
#define NO	((BOOL) 0)	/* Logic false */
#define YES	((BOOL) 1)	/* Logic true */

TEXT *acat(), *stralloc();

main () {

   
   fprintf (stdout, "%s\n", acat("", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555","666666",
      NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555","666666",
      "7777777", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555","666666",
      "7777777","88888888", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555","666666",
      "7777777","88888888","999999999", NULL));
   fflush (stdout);
   fprintf (stdout, "%s\n", acat("","1","22","333","4444","55555","666666",
      "7777777","88888888","999999999","10101010101010101010", NULL));
   fflush (stdout);

}


/* acat - allocating string concatenate (for up to 10 strings)

This (believed to be) portable routine will concatenate up to 10
strings.  Acat() is invoked by:

   newstring = acat (string1, string2 , . . . stringn, NULL);

  Acat is by no means elegant -- it even contains (horrors!) a
goto -- but it provides an amazingly useful function.

 */

TEXT *
acat (s0,s1,s2,s3,s4,s5,s6,s7,s8,s9,s10)
   TEXT *s0, *s1, *s2, *s3, *s4, *s5, *s6, *s7, *s8, *s9, *s10; {
   TEXT *instr[11];
   COUNT newlen, nstr, i;
   TEXT *news, *np, *op;
   
   nstr = 0;
   if (s0!=NULL)
      instr[nstr++] = s0;
   else
      goto got_em;
   if (s1!=NULL)
      instr[nstr++] = s1;
   else
      goto got_em;
   if (s2!=NULL)
      instr[nstr++] = s2;
   else
      goto got_em;
   if (s3!=NULL)
      instr[nstr++] = s3;
   else
      goto got_em;
   if (s4!=NULL)
      instr[nstr++] = s4;
   else
      goto got_em;
   if (s5!=NULL)
      instr[nstr++] = s5;
   else
      goto got_em;
   if (s6!=NULL)
      instr[nstr++] = s6;
   else
      goto got_em;
   if (s7!=NULL)
      instr[nstr++] = s7;
   else
      goto got_em;
   if (s8!=NULL)
      instr[nstr++] = s8;
   else
      goto got_em;
   if (s9!=NULL)
      instr[nstr++] = s9;
   else
      goto got_em;
   if (s10!=NULL)
      bugout ("More than 10 strings in acat()\n");
got_em:
   instr[nstr] = NULL;
   
   newlen = 0;
   for (i=0; i<nstr; i++)
      newlen += strlen(instr[i]);
   newlen += 1;		/* Allow space for an EOS */
   news = stralloc(newlen);
   np = news;
   for (i=0; i<nstr; i++) {
      op = instr[i];
      while ( (*np++ = *op++)!=EOS )
         ;
      np--;
      }

   return news;
   }


TEXT *progname = "test";

/* bugout - what to do when totally stuck or confused

Writes s to standard error, prefixed by the program name, then
exits with the "bomb" return code, 3.

 */

VOID
bugout (s)
   TEXT *s; {
   extern TEXT *progname;
   
   fprintf (stderr, "%s: %s", progname, s);
   exit (3);
   }

/* stralloc - string allocate

   Allocate n characters using calloc.  Bug out if there's no storage to get.
This routine really ought not use calloc.

 */

TEXT *
stralloc(n)
   COUNT n; {
   TEXT *news;
   
   news = (TEXT *) calloc(n,sizeof(TEXT));
   if (news==NULL)
      bugout ("Out of main memory in stralloc()\n");
   return news;
   }