/* This file is in the public domain. */

#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <strings.h>

#include "stdio-util.h"

typedef struct allocblk ALLOCBLK;
typedef struct rstrblk RSTRBLK;

struct allocblk {
  char **bufp;
  int *lenp;
  char *buf;
  int len;
  } ;

struct rstrblk {
  const char *buf;
  int len;
  off_t ptr;
  };

static int alloc_w(void *av, const char *b, int l)
{
 ALLOCBLK *a;

 a = av;
 if (a->bufp)
  { a->buf = realloc(a->buf,a->len+l);
    bcopy(b,a->buf+a->len,l);
  }
 a->len += l;
 return(l);
}

static int alloc_c(void *av)
{
 ALLOCBLK *a;

 a = av;
 if (a->bufp) *a->bufp = a->buf;
 if (a->lenp) *a->lenp = a->len;
 free(a);
 return(0);
}

FILE *fopen_alloc(char **bufp, int *lenp)
{
 FILE *f;
 ALLOCBLK *a;

 a = malloc(sizeof(ALLOCBLK));
 if (a == 0) return(0);
 a->bufp = bufp;
 a->lenp = lenp;
 a->buf = 0;
 a->len = 0;
 f = funopen(a,0,&alloc_w,0,&alloc_c);
 if (f == 0) free(a);
 return(f);
}

static int rstr_r(void *bv, char *buf, int len)
{
 RSTRBLK *b;
 int n;

 b = bv;
 if (b->ptr < 0)
  { errno = EINVAL;
    return(-1);
  }
 else if (b->ptr >= b->len)
  { return(0);
  }
 n = b->len - b->ptr;
 if (n > len) n = len;
 bcopy(b->buf+b->ptr,buf,n);
 b->ptr += n;
 return(n);
}

static int rstr_c(void *bv)
{
 free(bv);
 return(0);
}

FILE *fopen_rstr(const char *s, int l)
{
 RSTRBLK *b;
 FILE *f;

 b = malloc(sizeof(RSTRBLK));
 if (b == 0) return(0);
 if (l < 0) l = strlen(s);
 b->buf = s;
 b->len = l;
 b->ptr = 0;
 f = funopen(b,&rstr_r,0,0,&rstr_c);
 if (f == 0) free(b);
 return(f);
}

static int null_w(void *cookie __attribute__((__unused__)), const char *buf __attribute__((__unused__)), int len)
{
 return(len);
}

FILE *fopen_null(void)
{
 return(funopen(0,0,&null_w,0,0));
}

void print_lower(FILE *to, const char *s)
{
 for (;*s;s++) putc(tolower((unsigned char)*s),to);
}

int peekc(FILE *f)
{
 int c;

 c = getc(f);
 if (c != EOF) ungetc(c,f);
 return(c);
}