From ab6036630865eff8bb12dd51dfa6921b4607fc81 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sun, 19 Jul 2015 21:34:22 +0100 Subject: qemu-common.h: Document cutils.c string functions Add documentation comments for various utility string functions which we have implemented in util/cutils.c: pstrcpy() strpadcpy() pstrcat() strstart() stristart() qemu_strnlen() qemu_strsep() Signed-off-by: Peter Maydell Reviewed-by: Eric Blake Signed-off-by: Michael Tokarev --- include/qemu-common.h | 114 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 113 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/qemu-common.h b/include/qemu-common.h index 237d6547b3..fb3da6ca22 100644 --- a/include/qemu-common.h +++ b/include/qemu-common.h @@ -148,13 +148,125 @@ static inline bool is_help_option(const char *s) return !strcmp(s, "?") || !strcmp(s, "help"); } -/* cutils.c */ +/* util/cutils.c */ +/** + * pstrcpy: + * @buf: buffer to copy string into + * @buf_size: size of @buf in bytes + * @str: string to copy + * + * Copy @str into @buf, including the trailing NUL, but do not + * write more than @buf_size bytes. The resulting buffer is + * always NUL terminated (even if the source string was too long). + * If @buf_size is zero or negative then no bytes are copied. + * + * This function is similar to strncpy(), but avoids two of that + * function's problems: + * * if @str fits in the buffer, pstrcpy() does not zero-fill the + * remaining space at the end of @buf + * * if @str is too long, pstrcpy() will copy the first @buf_size-1 + * bytes and then add a NUL + */ void pstrcpy(char *buf, int buf_size, const char *str); +/** + * strpadcpy: + * @buf: buffer to copy string into + * @buf_size: size of @buf in bytes + * @str: string to copy + * @pad: character to pad the remainder of @buf with + * + * Copy @str into @buf (but *not* its trailing NUL!), and then pad the + * rest of the buffer with the @pad character. If @str is too large + * for the buffer then it is truncated, so that @buf contains the + * first @buf_size characters of @str, with no terminator. + */ void strpadcpy(char *buf, int buf_size, const char *str, char pad); +/** + * pstrcat: + * @buf: buffer containing existing string + * @buf_size: size of @buf in bytes + * @s: string to concatenate to @buf + * + * Append a copy of @s to the string already in @buf, but do not + * allow the buffer to overflow. If the existing contents of @buf + * plus @str would total more than @buf_size bytes, then write + * as much of @str as will fit followed by a NUL terminator. + * + * @buf must already contain a NUL-terminated string, or the + * behaviour is undefined. + * + * Returns: @buf. + */ char *pstrcat(char *buf, int buf_size, const char *s); +/** + * strstart: + * @str: string to test + * @val: prefix string to look for + * @ptr: NULL, or pointer to be written to indicate start of + * the remainder of the string + * + * Test whether @str starts with the prefix @val. + * If it does (including the degenerate case where @str and @val + * are equal) then return true. If @ptr is not NULL then a + * pointer to the first character following the prefix is written + * to it. If @val is not a prefix of @str then return false (and + * @ptr is not written to). + * + * Returns: true if @str starts with prefix @val, false otherwise. + */ int strstart(const char *str, const char *val, const char **ptr); +/** + * stristart: + * @str: string to test + * @val: prefix string to look for + * @ptr: NULL, or pointer to be written to indicate start of + * the remainder of the string + * + * Test whether @str starts with the case-insensitive prefix @val. + * This function behaves identically to strstart(), except that the + * comparison is made after calling qemu_toupper() on each pair of + * characters. + * + * Returns: true if @str starts with case-insensitive prefix @val, + * false otherwise. + */ int stristart(const char *str, const char *val, const char **ptr); +/** + * qemu_strnlen: + * @s: string + * @max_len: maximum number of bytes in @s to scan + * + * Return the length of the string @s, like strlen(), but do not + * examine more than @max_len bytes of the memory pointed to by @s. + * If no NUL terminator is found within @max_len bytes, then return + * @max_len instead. + * + * This function has the same behaviour as the POSIX strnlen() + * function. + * + * Returns: length of @s in bytes, or @max_len, whichever is smaller. + */ int qemu_strnlen(const char *s, int max_len); +/** + * qemu_strsep: + * @input: pointer to string to parse + * @delim: string containing delimiter characters to search for + * + * Locate the first occurrence of any character in @delim within + * the string referenced by @input, and replace it with a NUL. + * The location of the next character after the delimiter character + * is stored into @input. + * If the end of the string was reached without finding a delimiter + * character, then NULL is stored into @input. + * If @input points to a NULL pointer on entry, return NULL. + * The return value is always the original value of *@input (and + * so now points to a NUL-terminated string corresponding to the + * part of the input up to the first delimiter). + * + * This function has the same behaviour as the BSD strsep() function. + * + * Returns: the pointer originally in @input. + */ char *qemu_strsep(char **input, const char *delim); time_t mktimegm(struct tm *tm); int qemu_fls(int i); -- cgit v1.2.3