/*
* string_io.c --
*
* This file defines C-like input/output conversion routines for strings.
*
* Copyright (C) 1999, Massimo Dal Zotto <dz@cs.unitn.it>
*
* This software is distributed under the GNU General Public License
* either version 2, or (at your option) any later version.
*/
#include <ctype.h>
#include <string.h>
#include "postgres.h"
#include "utils/elog.h"
#include "utils/palloc.h"
#include "utils/builtins.h"
#include "string_io.h"
/* define this if you want to see iso-8859 characters */
#define ISO8859
#define MIN(x, y) ((x) < (y) ? (x) : (y))
#define VALUE(char) ((char) - '0')
#define DIGIT(val) ((val) + '0')
#define ISOCTAL(c) (((c) >= '0') && ((c) <= '7'))
#ifndef ISO8859
#define NOTPRINTABLE(c) (!isprint(c))
#else
#define NOTPRINTABLE(c) (!isprint(c) && ((c) < 0xa0))
#endif
/*
* string_output() --
*
* This function takes a pointer to a string data and an optional
* data size and returns a printable representation of the string
* translating all escape sequences to C-like \nnn or \c escapes.
* The function is used by output methods of various string types.
*
* Arguments:
* data - input data (can be NULL)
* size - optional size of data. A negative value indicates
* that data is a null terminated string.
*
* Returns:
* a pointer to a new string containing the printable
* representation of data.
*/
unsigned char *
string_output(unsigned char *data, int size)
{
register unsigned char c,
*p,
*r,
*result;
register int l,
len;
if (data == NULL)
{
result = (char *) palloc(2);
result[0] = '-';
result[1] = '\0';
return (result);
}
if (size < 0)
size = strlen(data);
/* adjust string length for escapes */
len = size;
for (p = data, l = size; l > 0; p++, l--)
{
switch (*p)
{
case '\\':
case '"':
case '\b':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
len++;
break;
case '{':
/* Escape beginning of string, to distinguish from arrays */
if (p == data)
len++;
break;
default:
if (NOTPRINTABLE(*p))
len += 3;
}
}
len++;
result = (char *) palloc(len);
for (p = data, r = result, l = size; (l > 0) && (c = *p); p++, l--)
{
switch (c)
{
case '\\':
case '"':
*r++ = '\\';
*r++ = c;
break;
case '\b':
*r++ = '\\';
*r++ = 'b';
break;
case '\f':
*r++ = '\\';
*r++ = 'f';
break;
case '\n':
*r++ = '\\';
*r++ = 'n';
break;
case '\r':
*r++ = '\\';
*r++ = 'r';
break;
case '\t':
*r++ = '\\';
*r++ = 't';
break;
case '\v':
*r++ = '\\';
*r++ = 'v';
break;
case '{':
/* Escape beginning of string, to distinguish from arrays */
if (p == data)
*r++ = '\\';
*r++ = c;
break;
default:
if (NOTPRINTABLE(c))
{
*r = '\\';
r += 3;
*r-- = DIGIT(c & 07);
c >>= 3;
*r-- = DIGIT(c & 07);
c >>= 3;
*r = DIGIT(c & 03);
r += 3;
}
else
*r++ = c;
}
}
*r = '\0';
return ((char *) result);
}
/*
* string_input() --
*
* This function accepts a C string in input and copies it into a new
* object allocated with palloc() translating all escape sequences.
* An optional header can be allocatd before the string, for example
* to hold the length of a varlena object.
* This function is not necessary for input from sql commands because
* the parser already does escape translation, all data input routines
* receive strings in internal form.
*
* Arguments:
* str - input string possibly with escapes
* size - the required size of new data. A value of 0
* indicates a variable size string, while a
* negative value indicates a variable size string
* of size not greater than this absolute value.
* hdrsize - size of an optional header to be allocated before
* the data. It must then be filled by the caller.
* rtn_size - an optional pointer to an int variable where the
* size of the new string is stored back.
*
* Returns:
* a pointer to the new string or the header.
*/
unsigned char *
string_input(unsigned char *str, int size, int hdrsize, int *rtn_size)
{
register unsigned char *p,
*r;
unsigned char *result;
int len;
if ((str == NULL) || (hdrsize < 0))
return (char *) NULL;
/* Compute result size */
len = strlen(str);
for (p = str; *p;)
{
if (*p++ == '\\')
{
if (ISOCTAL(*p))
{
if (ISOCTAL(*(p + 1)))
{
p++;
len--;
}
if (ISOCTAL(*(p + 1)))
{
p++;
len--;
}
}
if (*p)
p++;
len--;
}
}
/* result has variable length */
if (size == 0)
size = len + 1;
else
/* result has variable length with maximum size */
if (size < 0)
size = MIN(len, -size) + 1;
result = (char *) palloc(hdrsize + size);
memset(result, 0, hdrsize + size);
if (rtn_size)
*rtn_size = size;
r = result + hdrsize;
for (p = str; *p;)
{
register unsigned char c;
if ((c = *p++) == '\\')
{
switch (c = *p++)
{
case '\0':
p--;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
c = VALUE(c);
if (isdigit(*p))
c = (c << 3) + VALUE(*p++);
if (isdigit(*p))
c = (c << 3) + VALUE(*p++);
*r++ = c;
break;
case 'b':
*r++ = '\b';
break;
case 'f':
*r++ = '\f';
break;
case 'n':
*r++ = '\n';
break;
case 'r':
*r++ = '\r';
break;
case 't':
*r++ = '\t';
break;
case 'v':
*r++ = '\v';
break;
default:
*r++ = c;
}
}
else
*r++ = c;
}
return ((char *) result);
}
unsigned char *
c_charout(int32 c)
{
char str[2];
str[0] = (char) c;
str[1] = '\0';
return (string_output(str, 1));
}
/*
* This can be used for SET, bytea, text and unknown data types
*/
unsigned char *
c_textout(struct varlena * vlena)
{
int len = 0;
char *s = NULL;
if (vlena)
{
len = VARSIZE(vlena) - VARHDRSZ;
s = VARDATA(vlena);
}
return (string_output(s, len));
}
/*
* This can be used for varchar and bpchar strings
*/
unsigned char *
c_varcharout(unsigned char *s)
{
int len = 0;
if (s)
{
len = *(int32 *) s - 4;
s += 4;
}
return (string_output(s, len));
}
#if 0
struct varlena *
c_textin(unsigned char *str)
{
struct varlena *result;
int len;
if (str == NULL)
return ((struct varlena *) NULL);
result = (struct varlena *) string_input(str, 0, VARHDRSZ, &len);
VARSIZE(result) = len;
return (result);
}
int32 *
c_charin(unsigned char *str)
{
return (string_input(str, 1, 0, NULL));
}
#endif
/* end of file */
/*
* Local Variables:
* tab-width: 4
* c-indent-level: 4
* c-basic-offset: 4
* End:
*/