* The process of escaping byte buffer includes several parts. They are applied
* in the following sequence.
*
- * 1. The character is matched to the printable class, if asked, and in
- * case of match it passes through to the output.
- * 2. The character is not matched to the one from @only string and thus
+ * 1. The character is not matched to the one from @only string and thus
* must go as-is to the output.
- * 3. The character is checked if it falls into the class given by @flags.
+ * 2. The character is matched to the printable and ASCII classes, if asked,
+ * and in case of match it passes through to the output.
+ * 3. The character is matched to the printable or ASCII class, if asked,
+ * and in case of match it passes through to the output.
+ * 4. The character is checked if it falls into the class given by @flags.
* %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
* character. Note that they actually can't go together, otherwise
* %ESCAPE_HEX will be ignored.
*
* Caller must provide valid source and destination pointers. Be aware that
* destination buffer will not be NULL-terminated, thus caller have to append
- * it if needs. The supported flags are::
+ * it if needs. The supported flags are::
*
* %ESCAPE_SPACE: (special white space, not space itself)
* '\f' - form feed
* %ESCAPE_ANY:
* all previous together
* %ESCAPE_NP:
- * escape only non-printable characters (checked by isprint)
+ * escape only non-printable characters, checked by isprint()
* %ESCAPE_ANY_NP:
* all previous together
* %ESCAPE_HEX:
* '\xHH' - byte with hexadecimal value HH (2 digits)
+ * %ESCAPE_NA:
+ * escape only non-ascii characters, checked by isascii()
+ * %ESCAPE_NAP:
+ * escape only non-printable or non-ascii characters
+ * %ESCAPE_APPEND:
+ * append characters from @only to be escaped by the given classes
+ *
+ * %ESCAPE_APPEND would help to pass additional characters to the escaped, when
+ * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
+ *
+ * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
+ * higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
+ * It doesn't make much sense to use either of them without %ESCAPE_OCTAL
+ * or %ESCAPE_HEX, because they cover most of the other character classes.
+ * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
+ * the above.
*
* Return:
* The total size of the escaped output that would be generated for
char *p = dst;
char *end = p + osz;
bool is_dict = only && *only;
+ bool is_append = flags & ESCAPE_APPEND;
while (isz--) {
unsigned char c = *src++;
+ bool in_dict = is_dict && strchr(only, c);
/*
* Apply rules in the following sequence:
- * - the character is printable, when @flags has
- * %ESCAPE_NP bit set
* - the @only string is supplied and does not contain a
* character under question
+ * - the character is printable and ASCII, when @flags has
+ * %ESCAPE_NAP bit set
+ * - the character is printable, when @flags has
+ * %ESCAPE_NP bit set
+ * - the character is ASCII, when @flags has
+ * %ESCAPE_NA bit set
* - the character doesn't fall into a class of symbols
* defined by given @flags
* In these cases we just pass through a character to the
* output buffer.
+ *
+ * When %ESCAPE_APPEND is passed, the characters from @only
+ * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and
+ * %ESCAPE_NA cases.
*/
- if ((flags & ESCAPE_NP && isprint(c)) ||
- (is_dict && !strchr(only, c))) {
- /* do nothing */
- } else {
- if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
- continue;
+ if (!(is_append || in_dict) && is_dict &&
+ escape_passthrough(c, &p, end))
+ continue;
- if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
- continue;
+ if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
+ flags & ESCAPE_NAP && escape_passthrough(c, &p, end))
+ continue;
- if (flags & ESCAPE_NULL && escape_null(c, &p, end))
- continue;
+ if (!(is_append && in_dict) && isprint(c) &&
+ flags & ESCAPE_NP && escape_passthrough(c, &p, end))
+ continue;
- /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
- if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
- continue;
+ if (!(is_append && in_dict) && isascii(c) &&
+ flags & ESCAPE_NA && escape_passthrough(c, &p, end))
+ continue;
- if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
- continue;
- }
+ if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+ continue;
- escape_passthrough(c, &p, end);
- }
+ if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+ continue;
- return p - dst;
-}
-EXPORT_SYMBOL(string_escape_mem);
+ if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+ continue;
-int string_escape_mem_ascii(const char *src, size_t isz, char *dst,
- size_t osz)
-{
- char *p = dst;
- char *end = p + osz;
+ /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
+ if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
+ continue;
- while (isz--) {
- unsigned char c = *src++;
+ if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
+ continue;
- if (!isprint(c) || !isascii(c) || c == '"' || c == '\\')
- escape_hex(c, &p, end);
- else
- escape_passthrough(c, &p, end);
+ escape_passthrough(c, &p, end);
}
return p - dst;
}
-EXPORT_SYMBOL(string_escape_mem_ascii);
+EXPORT_SYMBOL(string_escape_mem);
/*
* Return an allocated string that has been escaped of special characters
projects / linux-2.6-microblaze.git / blobdiff