BSD 4_4 release

[unix-history] / usr / src / contrib / perl-4.036 / x2p / util.c

/* $RCSfile: util.c,v $$Revision: 4.0.1.1 $$Date: 91/06/07 12:20:35 $
*
*    Copyright (c) 1991, Larry Wall
*
*    You may distribute under the terms of either the GNU General Public
*    License or the Artistic License, as specified in the README file.
*
* $Log:        util.c,v $
* Revision 4.0.1.1  91/06/07  12:20:35  lwall
* patch4: new copyright notice
* 
* Revision 4.0  91/03/20  01:58:25  lwall
* 4.0 baseline.
* 
*/

#include <stdio.h>

#include "handy.h"
#include "EXTERN.h"
#include "a2p.h"
#include "INTERN.h"
#include "util.h"

#define FLUSH
#define MEM_SIZE unsigned int

static char nomem[] = "Out of memory!\n";

/* paranoid version of malloc */

static int an = 0;

char *
safemalloc(size)
MEM_SIZE size;
{
   char *ptr;
   char *malloc();

   ptr = malloc(size?size:1);  /* malloc(0) is NASTY on our system */
#ifdef DEBUGGING
   if (debug & 128)
       fprintf(stderr,"0x%x: (%05d) malloc %d bytes\n",ptr,an++,size);
#endif
   if (ptr != Nullch)
       return ptr;
   else {
       fputs(nomem,stdout) FLUSH;
       exit(1);
   }
   /*NOTREACHED*/
}

/* paranoid version of realloc */

char *
saferealloc(where,size)
char *where;
MEM_SIZE size;
{
   char *ptr;
   char *realloc();

   ptr = realloc(where,size?size:1);   /* realloc(0) is NASTY on our system */
#ifdef DEBUGGING
   if (debug & 128) {
       fprintf(stderr,"0x%x: (%05d) rfree\n",where,an++);
       fprintf(stderr,"0x%x: (%05d) realloc %d bytes\n",ptr,an++,size);
   }
#endif
   if (ptr != Nullch)
       return ptr;
   else {
       fputs(nomem,stdout) FLUSH;
       exit(1);
   }
   /*NOTREACHED*/
}

/* safe version of free */

safefree(where)
char *where;
{
#ifdef DEBUGGING
   if (debug & 128)
       fprintf(stderr,"0x%x: (%05d) free\n",where,an++);
#endif
   free(where);
}

/* safe version of string copy */

char *
safecpy(to,from,len)
char *to;
register char *from;
register int len;
{
   register char *dest = to;

   if (from != Nullch) 
       for (len--; len && (*dest++ = *from++); len--) ;
   *dest = '\0';
   return to;
}

/* copy a string up to some (non-backslashed) delimiter, if any */

char *
cpytill(to,from,delim)
register char *to, *from;
register int delim;
{
   for (; *from; from++,to++) {
       if (*from == '\\') {
           if (from[1] == delim)
               from++;
           else if (from[1] == '\\')
               *to++ = *from++;
       }
       else if (*from == delim)
           break;
       *to = *from;
   }
   *to = '\0';
   return from;
}


char *
cpy2(to,from,delim)
register char *to, *from;
register int delim;
{
   for (; *from; from++,to++) {
       if (*from == '\\')
           *to++ = *from++;
       else if (*from == '$')
           *to++ = '\\';
       else if (*from == delim)
           break;
       *to = *from;
   }
   *to = '\0';
   return from;
}

/* return ptr to little string in big string, NULL if not found */

char *
instr(big, little)
char *big, *little;

{
   register char *t, *s, *x;

   for (t = big; *t; t++) {
       for (x=t,s=little; *s; x++,s++) {
           if (!*x)
               return Nullch;
           if (*s != *x)
               break;
       }
       if (!*s)
           return t;
   }
   return Nullch;
}

/* copy a string to a safe spot */

char *
savestr(str)
char *str;
{
   register char *newaddr = safemalloc((MEM_SIZE)(strlen(str)+1));

   (void)strcpy(newaddr,str);
   return newaddr;
}

/* grow a static string to at least a certain length */

void
growstr(strptr,curlen,newlen)
char **strptr;
int *curlen;
int newlen;
{
   if (newlen > *curlen) {             /* need more room? */
       if (*curlen)
           *strptr = saferealloc(*strptr,(MEM_SIZE)newlen);
       else
           *strptr = safemalloc((MEM_SIZE)newlen);
       *curlen = newlen;
   }
}

/*VARARGS1*/
fatal(pat,a1,a2,a3,a4)
char *pat;
{
   fprintf(stderr,pat,a1,a2,a3,a4);
   exit(1);
}

/*VARARGS1*/
warn(pat,a1,a2,a3,a4)
char *pat;
{
   fprintf(stderr,pat,a1,a2,a3,a4);
}

static bool firstsetenv = TRUE;
extern char **environ;

void
setenv(nam,val)
char *nam, *val;
{
   register int i=envix(nam);          /* where does it go? */

   if (!environ[i]) {                  /* does not exist yet */
       if (firstsetenv) {              /* need we copy environment? */
           int j;
#ifndef lint
           char **tmpenv = (char**)    /* point our wand at memory */
               safemalloc((i+2) * sizeof(char*));
#else
           char **tmpenv = Null(char **);
#endif /* lint */
   
           firstsetenv = FALSE;
           for (j=0; j<i; j++)         /* copy environment */
               tmpenv[j] = environ[j];
           environ = tmpenv;           /* tell exec where it is now */
       }
#ifndef lint
       else
           environ = (char**) saferealloc((char*) environ,
               (i+2) * sizeof(char*));
                                       /* just expand it a bit */
#endif /* lint */
       environ[i+1] = Nullch;  /* make sure it's null terminated */
   }
   environ[i] = safemalloc(strlen(nam) + strlen(val) + 2);
                                       /* this may or may not be in */
                                       /* the old environ structure */
   sprintf(environ[i],"%s=%s",nam,val);/* all that work just for this */
}

int
envix(nam)
char *nam;
{
   register int i, len = strlen(nam);

   for (i = 0; environ[i]; i++) {
       if (strnEQ(environ[i],nam,len) && environ[i][len] == '=')
           break;                      /* strnEQ must come first to avoid */
   }                                   /* potential SEGV's */
   return i;
}