Messages in this thread Patch in this message | | | Subject | Re: [PATCH] Add lib/parser.c kernel-doc | From | Will Dyson <> | Date | Sun, 16 Nov 2003 17:37:05 -0500 |
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On Sun, 2003-11-16 at 03:16, Will Dyson wrote: > When I converted befs's option parsing to use the new lib/parser.c > functions, I had to read the functions (and the patch converting ext3) > in order to understand exactly how to use them. They are not that > complicated, but since I'd already read and (hopefully) understood the > functions, I figured I'd add a bit of documentation for others. > > I am not the author of the functions I am attempting to document here, > so any mistakes are just that: mistakes on my part.
Here is take 2, incorporating Matthew Wilcox's suggestions and sent as an attatchment to avoid word-wrap.
-- Will Dyson "Back off man, I'm a scientist!" -Dr. Peter Venkman # This is a BitKeeper generated patch for the following project: # Project Name: Linux kernel tree # This patch format is intended for GNU patch command version 2.5 or higher. # This patch includes the following deltas: # ChangeSet 1.1352 -> 1.1354 # lib/parser.c 1.2 -> 1.4 # include/linux/parser.h 1.1 -> 1.3 # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 03/11/16 will@thalience.(none) 1.1353 # Add documentation and comments to lib/parser.c and include/linux/parser.h # -------------------------------------------- # 03/11/16 will@thalience.(none) 1.1354 # Incorporate fixes/suggestions from Matthew Wilcox # -------------------------------------------- # diff -Nru a/include/linux/parser.h b/include/linux/parser.h --- a/include/linux/parser.h Sun Nov 16 17:32:10 2003 +++ b/include/linux/parser.h Sun Nov 16 17:32:10 2003 @@ -1,3 +1,14 @@ +/* + * linux/include/linux/parser.h + * + * Header for lib/parser.c + * Intended use of these functions is parsing filesystem argument lists, + * but could potentially be used anywhere else that simple option=arg + * parsing is required. + */ + + +/* associates an integer enumerator with a pattern string. */ struct match_token { int token; char *pattern; @@ -5,15 +16,16 @@ typedef struct match_token match_table_t[]; +/* Maximum number of arguments that match_token will find in a pattern */ enum {MAX_OPT_ARGS = 3}; +/* Describe the location within a string of a substring */ typedef struct { char *from; char *to; } substring_t; -int match_token(char *s, match_table_t table, substring_t args[]); - +int match_token(char *, match_table_t table, substring_t args[]); int match_int(substring_t *, int *result); int match_octal(substring_t *, int *result); int match_hex(substring_t *, int *result); diff -Nru a/lib/parser.c b/lib/parser.c --- a/lib/parser.c Sun Nov 16 17:32:10 2003 +++ b/lib/parser.c Sun Nov 16 17:32:10 2003 @@ -11,6 +11,17 @@ #include <linux/slab.h> #include <linux/string.h> +/** + * match_one: - Determines if a string matches a simple pattern + * @s: the string to examine for presense of the pattern + * @p: the string containing the pattern + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Determines if the pattern @p is present in string @s. Can only + * match extremely simple token=arg style patterns. If the pattern is found, + * the location(s) of the arguments will be returned in the @args array. + */ static int match_one(char *s, char *p, substring_t args[]) { char *meta; @@ -74,6 +85,20 @@ } } +/** + * match_token: - Find a token (and optional args) in a string + * @s: the string to examine for token/argument pairs + * @table: match_table_t describing the set of allowed option tokens and the + * arguments that may be associated with them. Must be terminated with a + * &struct match_token whose pattern is set to the NULL pointer. + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Detects which if any of a set of token strings has been passed + * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style + * format identifiers which will be taken into account when matching the + * tokens, and whose locations will be returned in the @args array. + */ int match_token(char *s, match_table_t table, substring_t args[]) { struct match_token *p; @@ -84,6 +109,16 @@ return p->token; } +/** + * match_number: scan a number in the given base from a substring_t + * @s: substring to be scanned + * @result: resulting integer on success + * @base: base to use when converting string + * + * Description: Given a &substring_t and a base, attempts to parse the substring + * as a number in that base. On success, sets @result to the integer represented + * by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ static int match_number(substring_t *s, int *result, int base) { char *endp; @@ -103,27 +138,71 @@ return ret; } +/** + * match_int: - scan a decimal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a decimal integer. On + * success, sets @result to the integer represented by the string and returns 0. + * Returns either -ENOMEM or -EINVAL on failure. + */ int match_int(substring_t *s, int *result) { return match_number(s, result, 0); } +/** + * match_octal: - scan an octal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as an octal integer. On + * success, sets @result to the integer represented by the string and returns + * 0. Returns either -ENOMEM or -EINVAL on failure. + */ int match_octal(substring_t *s, int *result) { return match_number(s, result, 8); } +/** + * match_hex: - scan a hex representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a hexadecimal integer. + * On success, sets @result to the integer represented by the string and + * returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ int match_hex(substring_t *s, int *result) { return match_number(s, result, 16); } +/** + * match_strcpy: - copies the characters from a substring_t to a string + * @to: string to copy characters to. + * @s: &substring_t to copy + * + * Description: Copies the set of characters represented by the given + * &substring_t @s to the c-style string @to. Caller guarantees that @to is + * large enough to hold the characters of @s. + */ void match_strcpy(char *to, substring_t *s) { memcpy(to, s->from, s->to - s->from); to[s->to - s->from] = '\0'; } +/** + * match_strdup: - allocate a new string with the contents of a substring_t + * @s: &substring_t to copy + * + * Description: Allocates and returns a string filled with the contents of + * the &substring_t @s. The caller is responsible for freeing the returned + * string with kfree(). + */ char *match_strdup(substring_t *s) { char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL); | |