scansup.c

application/octet-stream

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/*-------------------------------------------------------------------------
 *
 * scansup.c
 *      support routines for the lex/flex scanner, used by both the normal
 * backend as well as the bootstrap backend
 *
 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *      $Header: /home/projects/pgsql/cvsroot/pgsql/src/backend/parser/scansup.c,v 1.20 2001/01/24 19:43:03 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */

#include <ctype.h>

#include "postgres.h"
#include "miscadmin.h"
#include "parser/scansup.h"

/* ----------------
 *        scanstr
 *
 * if the string passed in has escaped codes, map the escape codes to actual
 * chars
 *
 * the string returned is palloc'd and should eventually be pfree'd by the
 * caller!
 * ----------------
 */

char *
scanstr(char *s)
{
    char       *newStr;
    int            len,
                i,
                j;

    if (s == NULL || s[0] == '\0')
        return pstrdup("");

    len = strlen(s);

    newStr = palloc(len + 1);    /* string cannot get longer */

    for (i = 0, j = 0; i < len; i++)
    {
        if (s[i] == '\'')
        {

            /*
             * Note: if scanner is working right, unescaped quotes can
             * only appear in pairs, so there should be another character.
             */
            i++;
            newStr[j] = s[i];
        }
        else if (s[i] == '\\')
        {
            i++;
            switch (s[i])
            {
                case 'b':
                    newStr[j] = '\b';
                    break;
                case 'f':
                    newStr[j] = '\f';
                    break;
                case 'n':
                    newStr[j] = '\n';
                    break;
                case 'r':
                    newStr[j] = '\r';
                    break;
                case 't':
                    newStr[j] = '\t';
                    break;
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                    {
                        int            k;
                        long        octVal = 0;

                        for (k = 0;
                             s[i + k] >= '0' && s[i + k] <= '7' && k < 3;
                             k++)
                            octVal = (octVal << 3) + (s[i + k] - '0');
                        i += k - 1;
                        newStr[j] = ((char) octVal);
                    }
                    break;
                default:
#ifdef MULTIBYTE 
                    newStr[j++] = '\\'; newStr[j] = s[i];
#else
                    newStr[j] = s[i];
#endif
                    break;
            }                    /* switch */
        }                        /* s[i] == '\\' */
        else
            newStr[j] = s[i];
        j++;
    }
    newStr[j] = '\0';
    return newStr;
}