1 // SPDX-License-Identifier: GPL-2.0-only
3  * Helpers for formatting and printing strings
23  * string_get_size - get the size in the specified units
114 		remainder -= 1000;  in string_get_size()
135  * parse_int_array_user - Split string into a sequence of integers
159 		ret = -ENOENT;  in parse_int_array_user()
165 		ret = -ENOMEM;  in parse_int_array_user()
209 	u8 num;  in unescape_octal()  local
214 	num = (*q++) & 7;  in unescape_octal()
215 	while (num < 32 && isodigit(*q) && (q - *src < 3)) {  in unescape_octal()
216 		num <<= 3;  in unescape_octal()
217 		num += (*q++) & 7;  in unescape_octal()
219 	*p = num;  in unescape_octal()
229 	u8 num;  in unescape_hex()  local
234 	num = digit = hex_to_bin(*q++);  in unescape_hex()
241 		num = (num << 4) | digit;  in unescape_hex()
243 	*p = num;  in unescape_hex()
275  * string_unescape - unquote characters in the given string
288  * destination buffer will always be NULL-terminated. Source string must be
289  * NULL-terminated as well.  The supported flags are::
292  *		'\f' - form feed
293  *		'\n' - new line
294  *		'\r' - carriage return
295  *		'\t' - horizontal tab
296  *		'\v' - vertical tab
298  *		'\NNN' - byte with octal value NNN (1 to 3 digits)
300  *		'\xHH' - byte with hexadecimal value HH (1 to 2 digits)
302  *		'\"' - double quote
303  *		'\\' - backslash
304  *		'\a' - alert (BEL)
305  *		'\e' - escape
317 	while (*src && --size) {  in string_unescape()
320 			size--;  in string_unescape()
344 	return out - dst;  in string_unescape()
488  * string_escape_mem - quote characters in the given memory buffer
494  * @only:	NULL-terminated string containing characters used to limit
504  *	   must go as-is to the output.
515  * destination buffer will not be NULL-terminated, thus caller have to append
519  *		'\f' - form feed
520  *		'\n' - new line
521  *		'\r' - carriage return
522  *		'\t' - horizontal tab
523  *		'\v' - vertical tab
525  *		'\"' - double quote
526  *		'\\' - backslash
527  *		'\a' - alert (BEL)
528  *		'\e' - escape
530  *		'\0' - null
532  *		'\NNN' - byte with octal value NNN (3 digits)
536  *		escape only non-printable characters, checked by isprint()
540  *		'\xHH' - byte with hexadecimal value HH (2 digits)
542  *		escape only non-ascii characters, checked by isascii()
544  *		escape only non-printable or non-ascii characters
572 	while (isz--) {  in string_escape_mem()
578 		 *	- the @only string is supplied and does not contain a  in string_escape_mem()
580 		 *	- the character is printable and ASCII, when @flags has  in string_escape_mem()
582 		 *	- the character is printable, when @flags has  in string_escape_mem()
584 		 *	- the character is ASCII, when @flags has  in string_escape_mem()
586 		 *	- the character doesn't fall into a class of symbols  in string_escape_mem()
630 	return p - dst;  in string_escape_mem()
662  * Returns allocated NULL-terminated string containing process
663  * command line, with inter-argument NULLs replaced with spaces,
675 	res = get_cmdline(task, buffer, PAGE_SIZE - 1);  in kstrdup_quotable_cmdline()
678 	/* Collapse trailing NULLs, leave res pointing to last non-NULL. */  in kstrdup_quotable_cmdline()
679 	while (--res >= 0 && buffer[res] == '\0')  in kstrdup_quotable_cmdline()
682 	/* Replace inter-argument NULLs. */  in kstrdup_quotable_cmdline()
695  * Returns allocated NULL-terminated string containing pathname,
738  * kasprintf_strarray - allocate and fill array of sequential strings
743  * Allocates and fills @n strings using pattern "%s-%zu", where prefix
747  * Returns array of strings or NULL when memory can't be allocated.
759 		names[i] = kasprintf(gfp, "%s-%zu", prefix, i);  in kasprintf_strarray()
771  * kfree_strarray - free a number of dynamically allocated strings contained
774  * @array: Dynamically allocated array of strings to free.
775  * @n: Number of strings (starting from the beginning of the array) to free.
777  * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid
778  * use-cases. If @array is NULL, the function does nothing.
802 	kfree_strarray(array->array, array->n);  in devm_kfree_strarray()
811 		return ERR_PTR(-ENOMEM);  in devm_kasprintf_strarray()
813 	ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);  in devm_kasprintf_strarray()
814 	if (!ptr->array) {  in devm_kasprintf_strarray()
816 		return ERR_PTR(-ENOMEM);  in devm_kasprintf_strarray()
819 	ptr->n = n;  in devm_kasprintf_strarray()
822 	return ptr->array;  in devm_kasprintf_strarray()
827  * strscpy_pad() - Copy a C-string into a sized buffer
834  * buffer is always %NUL terminated, unless it's zero-sized.
844  * * -E2BIG if count is 0 or @src was truncated.
851 	if (written < 0 || written == count - 1)  in strscpy_pad()
854 	memset(dest + written + 1, 0, count - written - 1);  in strscpy_pad()
861  * skip_spaces - Removes leading whitespace from @str.
864  * Returns a pointer to the first non-whitespace character in @str.
875  * strim - Removes leading and trailing whitespace from @s.
878  * Note that the first trailing whitespace is replaced with a %NUL-terminator
879  * in the given string @s. Returns a pointer to the first non-whitespace
891 	end = s + size - 1;  in strim()
893 		end--;  in strim()
901  * sysfs_streq - return true if strings are equal, modulo trailing newline
905  * This routine returns true iff two strings are equal, treating both
906  * NUL and newline-then-NUL as equivalent string terminations.  It's
907  * geared for use with sysfs input strings, which generally terminate
928  * match_string - matches given string in an array
929  * @array:	array of strings
930  * @n:		number of strings in the array or -1 for NULL terminated arrays
933  * This routine will look for a string in an array of strings up to the
934  * n-th element in the array or until the first NULL element.
936  * Historically the value of -1 for @n, was used to search in arrays that
942  * index of a @string in the @array if matches, or %-EINVAL otherwise.
957 	return -EINVAL;  in match_string()
962  * __sysfs_match_string - matches given string in an array
963  * @array: array of strings
964  * @n: number of strings in the array or -1 for NULL terminated arrays
967  * Returns index of @str in the @array or -EINVAL, just like match_string().
970  * This routine will look for a string in an array of strings up to the
971  * n-th element in the array or until the first NULL element.
973  * Historically the value of -1 for @n, was used to search in arrays that
991 	return -EINVAL;  in __sysfs_match_string()
996  * strreplace - Replace all occurrences of character in string.
1017  * memcpy_and_pad - Copy one buffer to another with padding
1029 		memset(dest + count, pad,  dest_len - count);  in memcpy_and_pad()
1037 /* These are placeholders for fortify compile-time warnings. */