src/lib/str-sanitize.c

	str-sanitize.c revision 76b43e4417bab52e913da39b5f5bc2a130d3f149
/* Copyright (c) 2004-2008 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "str.h"
#include "str-sanitize.h"

static size_t str_sanitize_skip_start(const char *src, size_t max_len)
{
    size_t i;

    for (i = 0; i < max_len; i++) {
        if (((unsigned char)src[i] & 0x7f) < 32)
            break;
    }
    return i;
}

void str_sanitize_append(string_t *dest, const char *src, size_t max_len)
{
    size_t i;

    i = str_sanitize_skip_start(src, max_len);
    str_append_n(dest, src, i);

    for (; i < max_len && src[i] != '\0'; i++) {
        if (((unsigned char)src[i] & 0x7f) < 32)
            str_append_c(dest, '?');
        else
            str_append_c(dest, src[i]);
    }

    if (src[i] != '\0') {
        str_truncate(dest, str_len(dest) <= 3 ? 0 : str_len(dest)-3);
        str_append(dest, "...");
    }
}

const char *str_sanitize(const char *src, size_t max_len)
{
    string_t *str;
    size_t i;

    if (src == NULL)
        return NULL;

    i = str_sanitize_skip_start(src, max_len);
    if (src[i] == '\0')
        return src;

    str = t_str_new(I_MIN(max_len, 256));
    str_append_n(str, src, i);
    str_sanitize_append(str, src + i, max_len - i);
    return str_c(str);
}