ANSI

[unix-history] / usr / src / usr.bin / window / string.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Edward Wang at The University of California, Berkeley.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)string.c    3.13 (Berkeley) %G%";
#endif /* not lint */

#include "string.h"

char *malloc();

char *
str_cpy(s)
register char *s;
{
       char *str;
       register char *p;

       str = p = str_alloc(strlen(s) + 1);
       if (p == 0)
               return 0;
       while (*p++ = *s++)
               ;
       return str;
}

char *
str_ncpy(s, n)
register char *s;
register n;
{
       int l = strlen(s);
       char *str;
       register char *p;

       if (n > l)
               n = l;
       str = p = str_alloc(n + 1);
       if (p == 0)
               return 0;
       while (--n >= 0)
               *p++ = *s++;
       *p = 0;
       return str;
}

char *
str_itoa(i)
int i;
{
       char buf[30];

       (void) sprintf(buf, "%d", i);
       return str_cpy(buf);
}

char *
str_cat(s1, s2)
char *s1, *s2;
{
       char *str;
       register char *p, *q;

       str = p = str_alloc(strlen(s1) + strlen(s2) + 1);
       if (p == 0)
               return 0;
       for (q = s1; *p++ = *q++;)
               ;
       for (q = s2, p--; *p++ = *q++;)
               ;
       return str;
}

/*
* match s against p.
* s can be a prefix of p with at least min characters.
*/
str_match(s, p, min)
register char *s, *p;
register min;
{
       for (; *s && *p && *s == *p; s++, p++, min--)
               ;
       return *s == *p || *s == 0 && min <= 0;
}

#ifdef STR_DEBUG
char *
str_alloc(l)
int l;
{
       register struct string *s;

       s = (struct string *) malloc((unsigned)l + str_offset);
       if (s == 0)
               return 0;
       if (str_head.s_forw == 0)
               str_head.s_forw = str_head.s_back = &str_head;
       s->s_forw = str_head.s_forw;
       s->s_back = &str_head;
       str_head.s_forw = s;
       s->s_forw->s_back = s;
       return s->s_data;
}

str_free(str)
char *str;
{
       register struct string *s;

       for (s = str_head.s_forw; s != &str_head && s->s_data != str;
            s = s->s_forw)
               ;
       if (s == &str_head)
               abort();
       s->s_back->s_forw = s->s_forw;
       s->s_forw->s_back = s->s_back;
       free((char *)s);
}
#endif