/*
* include/common/standard.h
* This files contains some general purpose functions and macros.
*
* Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_STANDARD_H
#define _COMMON_STANDARD_H
#include <limits.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <common/config.h>
#include <eb32tree.h>
#ifndef LLONG_MAX
# define LLONG_MAX 9223372036854775807LL
# define LLONG_MIN (-LLONG_MAX - 1LL)
#endif
#ifndef ULLONG_MAX
# define ULLONG_MAX (LLONG_MAX * 2ULL + 1)
#endif
/****** string-specific macros and functions ******/
/* if a > max, then bound <a> to <max>. The macro returns the new <a> */
#define UBOUND(a, max) ({ typeof(a) b = (max); if ((a) > b) (a) = b; (a); })
/* if a < min, then bound <a> to <min>. The macro returns the new <a> */
#define LBOUND(a, min) ({ typeof(a) b = (min); if ((a) < b) (a) = b; (a); })
/* returns 1 only if only zero or one bit is set in X, which means that X is a
* power of 2, and 0 otherwise */
#define POWEROF2(x) (((x) & ((x)-1)) == 0)
/* operators to compare values. They're ordered that way so that the lowest bit
* serves as a negation for the test and contains all tests that are not equal.
*/
enum {
STD_OP_LE = 0, STD_OP_GT = 1,
STD_OP_EQ = 2, STD_OP_NE = 3,
STD_OP_GE = 4, STD_OP_LT = 5,
};
/*
* copies at most <size-1> chars from <src> to <dst>. Last char is always
* set to 0, unless <size> is 0. The number of chars copied is returned
* (excluding the terminating zero).
* This code has been optimized for size and speed : on x86, it's 45 bytes
* long, uses only registers, and consumes only 4 cycles per char.
*/
extern int strlcpy2(char *dst, const char *src, int size);
/*
* This function simply returns a locally allocated string containing
* the ascii representation for number 'n' in decimal.
*/
extern char itoa_str[][171];
extern char *ultoa_r(unsigned long n, char *buffer, int size);
extern const char *ulltoh_r(unsigned long long n, char *buffer, int size);
static inline const char *ultoa(unsigned long n)
{
return ultoa_r(n, itoa_str[0], sizeof(itoa_str[0]));
}
/*
* unsigned long long ASCII representation
*
* return the last char '\0' or NULL if no enough
* space in dst
*/
char *ulltoa(unsigned long long n, char *dst, size_t size);
/*
* unsigned long ASCII representation
*
* return the last char '\0' or NULL if no enough
* space in dst
*/
char *ultoa_o(unsigned long n, char *dst, size_t size);
/*
* signed long ASCII representation
*
* return the last char '\0' or NULL if no enough
* space in dst
*/
char *ltoa_o(long int n, char *dst, size_t size);
/*
* signed long long ASCII representation
*
* return the last char '\0' or NULL if no enough
* space in dst
*/
char *lltoa(long long n, char *dst, size_t size);
/*
* write a ascii representation of a unsigned into dst,
* return a pointer to the last character
* Pad the ascii representation with '0', using size.
*/
char *utoa_pad(unsigned int n, char *dst, size_t size);
/* Fast macros to convert up to 10 different parameters inside a same call of
* expression.
*/
#define U2A0(n) ({ ultoa_r((n), itoa_str[0], sizeof(itoa_str[0])); })
#define U2A1(n) ({ ultoa_r((n), itoa_str[1], sizeof(itoa_str[1])); })
#define U2A2(n) ({ ultoa_r((n), itoa_str[2], sizeof(itoa_str[2])); })
#define U2A3(n) ({ ultoa_r((n), itoa_str[3], sizeof(itoa_str[3])); })
#define U2A4(n) ({ ultoa_r((n), itoa_str[4], sizeof(itoa_str[4])); })
#define U2A5(n) ({ ultoa_r((n), itoa_str[5], sizeof(itoa_str[5])); })
#define U2A6(n) ({ ultoa_r((n), itoa_str[6], sizeof(itoa_str[6])); })
#define U2A7(n) ({ ultoa_r((n), itoa_str[7], sizeof(itoa_str[7])); })
#define U2A8(n) ({ ultoa_r((n), itoa_str[8], sizeof(itoa_str[8])); })
#define U2A9(n) ({ ultoa_r((n), itoa_str[9], sizeof(itoa_str[9])); })
/* The same macros provide HTML encoding of numbers */
#define U2H0(n) ({ ulltoh_r((n), itoa_str[0], sizeof(itoa_str[0])); })
#define U2H1(n) ({ ulltoh_r((n), itoa_str[1], sizeof(itoa_str[1])); })
#define U2H2(n) ({ ulltoh_r((n), itoa_str[2], sizeof(itoa_str[2])); })
#define U2H3(n) ({ ulltoh_r((n), itoa_str[3], sizeof(itoa_str[3])); })
#define U2H4(n) ({ ulltoh_r((n), itoa_str[4], sizeof(itoa_str[4])); })
#define U2H5(n) ({ ulltoh_r((n), itoa_str[5], sizeof(itoa_str[5])); })
#define U2H6(n) ({ ulltoh_r((n), itoa_str[6], sizeof(itoa_str[6])); })
#define U2H7(n) ({ ulltoh_r((n), itoa_str[7], sizeof(itoa_str[7])); })
#define U2H8(n) ({ ulltoh_r((n), itoa_str[8], sizeof(itoa_str[8])); })
#define U2H9(n) ({ ulltoh_r((n), itoa_str[9], sizeof(itoa_str[9])); })
/*
* This function simply returns a locally allocated string containing the ascii
* representation for number 'n' in decimal, unless n is 0 in which case it
* returns the alternate string (or an empty string if the alternate string is
* NULL). It use is intended for limits reported in reports, where it's
* desirable not to display anything if there is no limit. Warning! it shares
* the same vector as ultoa_r().
*/
extern const char *limit_r(unsigned long n, char *buffer, int size, const char *alt);
/* Fast macros to convert up to 10 different parameters inside a same call of
* expression. Warning! they share the same vectors as U2A*!
*/
#define LIM2A0(n, alt) ({ limit_r((n), itoa_str[0], sizeof(itoa_str[0]), (alt)); })
#define LIM2A1(n, alt) ({ limit_r((n), itoa_str[1], sizeof(itoa_str[1]), (alt)); })
#define LIM2A2(n, alt) ({ limit_r((n), itoa_str[2], sizeof(itoa_str[2]), (alt)); })
#define LIM2A3(n, alt) ({ limit_r((n), itoa_str[3], sizeof(itoa_str[3]), (alt)); })
#define LIM2A4(n, alt) ({ limit_r((n), itoa_str[4], sizeof(itoa_str[4]), (alt)); })
#define LIM2A5(n, alt) ({ limit_r((n), itoa_str[5], sizeof(itoa_str[5]), (alt)); })
#define LIM2A6(n, alt) ({ limit_r((n), itoa_str[6], sizeof(itoa_str[6]), (alt)); })
#define LIM2A7(n, alt) ({ limit_r((n), itoa_str[7], sizeof(itoa_str[7]), (alt)); })
#define LIM2A8(n, alt) ({ limit_r((n), itoa_str[8], sizeof(itoa_str[8]), (alt)); })
#define LIM2A9(n, alt) ({ limit_r((n), itoa_str[9], sizeof(itoa_str[9]), (alt)); })
/*
* Returns non-zero if character <s> is a hex digit (0-9, a-f, A-F), else zero.
*/
extern int ishex(char s);
/*
* Return integer equivalent of character <c> for a hex digit (0-9, a-f, A-F),
* otherwise -1.
*/
extern int hex2i(int c);
/*
* Checks <name> for invalid characters. Valid chars are [A-Za-z0-9_:.-]. If an
* invalid character is found, a pointer to it is returned. If everything is
* fine, NULL is returned.
*/
extern const char *invalid_char(const char *name);
/*
* Checks <domainname> for invalid characters. Valid chars are [A-Za-z0-9_.-].
* If an invalid character is found, a pointer to it is returned.
* If everything is fine, NULL is returned.
*/
extern const char *invalid_domainchar(const char *name);
/*
* converts <str> to a struct sockaddr_un* which is locally allocated.
* The format is "/path", where "/path" is a path to a UNIX domain socket.
*/
struct sockaddr_un *str2sun(const char *str);
/*
* converts <str> to a struct sockaddr_storage* which is locally allocated. The
* string is assumed to contain only an address, no port. The address can be a
* dotted IPv4 address, an IPv6 address, a host name, or empty or "*" to
* indicate INADDR_ANY. NULL is returned if the host part cannot be resolved.
* The return address will only have the address family and the address set,
* all other fields remain zero. The string is not supposed to be modified.
* The IPv6 '::' address is IN6ADDR_ANY.
*/
struct sockaddr_storage *str2ip(const char *str);
/*
* converts <str> to a locally allocated struct sockaddr_storage *.
* The format is "addr[:[port]]", where "addr" can be a dotted IPv4 address, an
* IPv6 address, a host name, or empty or "*" to indicate INADDR_ANY. If an IPv6
* address wants to ignore port, it must be terminated by a trailing colon (':').
* The IPv6 '::' address is IN6ADDR_ANY, so in order to bind to a given port on
* IPv6, use ":::port". NULL is returned if the host part cannot be resolved.
*/
struct sockaddr_storage *str2sa(const char *str);
/*
* converts <str> to a locally allocated struct sockaddr_storage *, and a
* port range consisting in two integers. The low and high end are always set
* even if the port is unspecified, in which case (0,0) is returned. The low
* port is set in the sockaddr. Thus, it is enough to check the size of the
* returned range to know if an array must be allocated or not. The format is
* "addr[:[port[-port]]]", where "addr" can be a dotted IPv4 address, an IPv6
* address, a host name, or empty or "*" to indicate INADDR_ANY. If an IPv6
* address wants to ignore port, it must be terminated by a trailing colon (':').
* The IPv6 '::' address is IN6ADDR_ANY, so in order to bind to a given port on
* IPv6, use ":::port". NULL is returned if the host part cannot be resolved.
*/
struct sockaddr_storage *str2sa_range(const char *str, int *low, int *high);
/* converts <str> to a struct in_addr containing a network mask. It can be
* passed in dotted form (255.255.255.0) or in CIDR form (24). It returns 1
* if the conversion succeeds otherwise non-zero.
*/
int str2mask(const char *str, struct in_addr *mask);
/*
* converts <str> to two struct in_addr* which must be pre-allocated.
* The format is "addr[/mask]", where "addr" cannot be empty, and mask
* is optionnal and either in the dotted or CIDR notation.
* Note: "addr" can also be a hostname. Returns 1 if OK, 0 if error.
*/
int str2net(const char *str, struct in_addr *addr, struct in_addr *mask);
/*
* converts <str> to two struct in6_addr* which must be pre-allocated.
* The format is "addr[/mask]", where "addr" cannot be empty, and mask
* is an optionnal number of bits (128 being the default).
* Returns 1 if OK, 0 if error.
*/
int str62net(const char *str, struct in6_addr *addr, unsigned char *mask);
/*
* Parse IP address found in url.
*/
int url2ipv4(const char *addr, struct in_addr *dst);
/*
* Resolve destination server from URL. Convert <str> to a sockaddr_storage*.
*/
int url2sa(const char *url, int ulen, struct sockaddr_storage *addr);
/* Tries to convert a sockaddr_storage address to text form. Upon success, the
* address family is returned so that it's easy for the caller to adapt to the
* output format. Zero is returned if the address family is not supported. -1
* is returned upon error, with errno set. AF_INET, AF_INET6 and AF_UNIX are
* supported.
*/
int addr_to_str(struct sockaddr_storage *addr, char *str, int size);
/* will try to encode the string <string> replacing all characters tagged in
* <map> with the hexadecimal representation of their ASCII-code (2 digits)
* prefixed by <escape>, and will store the result between <start> (included)
* and <stop> (excluded), and will always terminate the string with a '\0'
* before <stop>. The position of the '\0' is returned if the conversion
* completes. If bytes are missing between <start> and <stop>, then the
* conversion will be incomplete and truncated. If <stop> <= <start>, the '\0'
* cannot even be stored so we return <start> without writing the 0.
* The input string must also be zero-terminated.
*/
extern const char hextab[];
char *encode_string(char *start, char *stop,
const char escape, const fd_set *map,
const char *string);
/* Decode an URL-encoded string in-place. The resulting string might
* be shorter. If some forbidden characters are found, the conversion is
* aborted, the string is truncated before the issue and non-zero is returned,
* otherwise the operation returns non-zero indicating success.
*/
int url_decode(char *string);
/* This one is 6 times faster than strtoul() on athlon, but does
* no check at all.
*/
static inline unsigned int __str2ui(const char *s)
{
unsigned int i = 0;
while (*s) {
i = i * 10 - '0';
i += (unsigned char)*s++;
}
return i;
}
/* This one is 5 times faster than strtoul() on athlon with checks.
* It returns the value of the number composed of all valid digits read.
*/
static inline unsigned int __str2uic(const char *s)
{
unsigned int i = 0;
unsigned int j;
while (1) {
j = (*s++) - '0';
if (j > 9)
break;
i *= 10;
i += j;
}
return i;
}
/* This one is 28 times faster than strtoul() on athlon, but does
* no check at all!
*/
static inline unsigned int __strl2ui(const char *s, int len)
{
unsigned int i = 0;
while (len-- > 0) {
i = i * 10 - '0';
i += (unsigned char)*s++;
}
return i;
}
/* This one is 7 times faster than strtoul() on athlon with checks.
* It returns the value of the number composed of all valid digits read.
*/
static inline unsigned int __strl2uic(const char *s, int len)
{
unsigned int i = 0;
unsigned int j, k;
while (len-- > 0) {
j = (*s++) - '0';
k = i * 10;
if (j > 9)
break;
i = k + j;
}
return i;
}
/* This function reads an unsigned integer from the string pointed to by <s>
* and returns it. The <s> pointer is adjusted to point to the first unread
* char. The function automatically stops at <end>.
*/
static inline unsigned int __read_uint(const char **s, const char *end)
{
const char *ptr = *s;
unsigned int i = 0;
unsigned int j, k;
while (ptr < end) {
j = *ptr - '0';
k = i * 10;
if (j > 9)
break;
i = k + j;
ptr++;
}
*s = ptr;
return i;
}
extern unsigned int str2ui(const char *s);
extern unsigned int str2uic(const char *s);
extern unsigned int strl2ui(const char *s, int len);
extern unsigned int strl2uic(const char *s, int len);
extern int strl2ic(const char *s, int len);
extern int strl2irc(const char *s, int len, int *ret);
extern int strl2llrc(const char *s, int len, long long *ret);
extern unsigned int read_uint(const char **s, const char *end);
unsigned int inetaddr_host(const char *text);
unsigned int inetaddr_host_lim(const char *text, const char *stop);
unsigned int inetaddr_host_lim_ret(char *text, char *stop, char **ret);
static inline char *cut_crlf(char *s) {
while (*s != '\r' || *s == '\n') {
char *p = s++;
if (!*p)
return p;
}
*s++ = 0;
return s;
}
static inline char *ltrim(char *s, char c) {
if (c)
while (*s == c)
s++;
return s;
}
static inline char *rtrim(char *s, char c) {
char *p = s + strlen(s);
while (p-- > s)
if (*p == c)
*p = '\0';
else
break;
return s;
}
static inline char *alltrim(char *s, char c) {
rtrim(s, c);
return ltrim(s, c);
}
/* This function converts the time_t value <now> into a broken out struct tm
* which must be allocated by the caller. It is highly recommended to use this
* function intead of localtime() because that one requires a time_t* which
* is not always compatible with tv_sec depending on OS/hardware combinations.
*/
static inline void get_localtime(const time_t now, struct tm *tm)
{
localtime_r(&now, tm);
}
/* This function converts the time_t value <now> into a broken out struct tm
* which must be allocated by the caller. It is highly recommended to use this
* function intead of gmtime() because that one requires a time_t* which
* is not always compatible with tv_sec depending on OS/hardware combinations.
*/
static inline void get_gmtime(const time_t now, struct tm *tm)
{
gmtime_r(&now, tm);
}
/* This function parses a time value optionally followed by a unit suffix among
* "d", "h", "m", "s", "ms" or "us". It converts the value into the unit
* expected by the caller. The computation does its best to avoid overflows.
* The value is returned in <ret> if everything is fine, and a NULL is returned
* by the function. In case of error, a pointer to the error is returned and
* <ret> is left untouched.
*/
extern const char *parse_time_err(const char *text, unsigned *ret, unsigned unit_flags);
extern const char *parse_size_err(const char *text, unsigned *ret);
/* unit flags to pass to parse_time_err */
#define TIME_UNIT_US 0x0000
#define TIME_UNIT_MS 0x0001
#define TIME_UNIT_S 0x0002
#define TIME_UNIT_MIN 0x0003
#define TIME_UNIT_HOUR 0x0004
#define TIME_UNIT_DAY 0x0005
#define TIME_UNIT_MASK 0x0007
#define SEC 1
#define MINUTE (60 * SEC)
#define HOUR (60 * MINUTE)
#define DAY (24 * HOUR)
/* Multiply the two 32-bit operands and shift the 64-bit result right 32 bits.
* This is used to compute fixed ratios by setting one of the operands to
* (2^32*ratio).
*/
static inline unsigned int mul32hi(unsigned int a, unsigned int b)
{
return ((unsigned long long)a * b) >> 32;
}
/* gcc does not know when it can safely divide 64 bits by 32 bits. Use this
* function when you know for sure that the result fits in 32 bits, because
* it is optimal on x86 and on 64bit processors.
*/
static inline unsigned int div64_32(unsigned long long o1, unsigned int o2)
{
unsigned int result;
#ifdef __i386__
asm("divl %2"
: "=a" (result)
: "A"(o1), "rm"(o2));
#else
result = o1 / o2;
#endif
return result;
}
/* copies at most <n> characters from <src> and always terminates with '\0' */
char *my_strndup(const char *src, int n);
/* This function returns the first unused key greater than or equal to <key> in
* ID tree <root>. Zero is returned if no place is found.
*/
unsigned int get_next_id(struct eb_root *root, unsigned int key);
/* This function compares a sample word possibly followed by blanks to another
* clean word. The compare is case-insensitive. 1 is returned if both are equal,
* otherwise zero. This intends to be used when checking HTTP headers for some
* values.
*/
int word_match(const char *sample, int slen, const char *word, int wlen);
/* Convert a fixed-length string to an IP address. Returns 0 in case of error,
* or the number of chars read in case of success.
*/
int buf2ip(const char *buf, size_t len, struct in_addr *dst);
/* To be used to quote config arg positions. Returns the string at <ptr>
* surrounded by simple quotes if <ptr> is valid and non-empty, or "end of line"
* if ptr is NULL or empty. The string is locally allocated.
*/
const char *quote_arg(const char *ptr);
/* returns an operator among STD_OP_* for string <str> or < 0 if unknown */
int get_std_op(const char *str);
/* hash a 32-bit integer to another 32-bit integer */
extern unsigned int full_hash(unsigned int a);
static inline unsigned int __full_hash(unsigned int a)
{
/* This function is one of Bob Jenkins' full avalanche hashing
* functions, which when provides quite a good distribution for little
* input variations. The result is quite suited to fit over a 32-bit
* space with enough variations so that a randomly picked number falls
* equally before any server position.
* Check http://burtleburtle.net/bob/hash/integer.html for more info.
*/
a = (a+0x7ed55d16) + (a<<12);
a = (a^0xc761c23c) ^ (a>>19);
a = (a+0x165667b1) + (a<<5);
a = (a+0xd3a2646c) ^ (a<<9);
a = (a+0xfd7046c5) + (a<<3);
a = (a^0xb55a4f09) ^ (a>>16);
/* ensure values are better spread all around the tree by multiplying
* by a large prime close to 3/4 of the tree.
*/
return a * 3221225473U;
}
/* returns non-zero if addr has a valid and non-null IPv4 or IPv6 address,
* otherwise zero.
*/
static inline int is_addr(struct sockaddr_storage *addr)
{
int i;
switch (addr->ss_family) {
case AF_INET:
return *(int *)&((struct sockaddr_in *)addr)->sin_addr;
case AF_INET6:
for (i = 0; i < sizeof(struct in6_addr) / sizeof(int); i++)
if (((int *)&((struct sockaddr_in6 *)addr)->sin6_addr)[i] != 0)
return ((int *)&((struct sockaddr_in6 *)addr)->sin6_addr)[i];
}
return 0;
}
/* returns port in network byte order */
static inline int get_net_port(struct sockaddr_storage *addr)
{
switch (addr->ss_family) {
case AF_INET:
return ((struct sockaddr_in *)addr)->sin_port;
case AF_INET6:
return ((struct sockaddr_in6 *)addr)->sin6_port;
}
return 0;
}
/* returns port in host byte order */
static inline int get_host_port(struct sockaddr_storage *addr)
{
switch (addr->ss_family) {
case AF_INET:
return ntohs(((struct sockaddr_in *)addr)->sin_port);
case AF_INET6:
return ntohs(((struct sockaddr_in6 *)addr)->sin6_port);
}
return 0;
}
/* returns address len for <addr>'s family, 0 for unknown families */
static inline int get_addr_len(const struct sockaddr_storage *addr)
{
switch (addr->ss_family) {
case AF_INET:
return sizeof(struct sockaddr_in);
case AF_INET6:
return sizeof(struct sockaddr_in6);
case AF_UNIX:
return sizeof(struct sockaddr_un);
}
return 0;
}
/* set port in host byte order */
static inline int set_net_port(struct sockaddr_storage *addr, int port)
{
switch (addr->ss_family) {
case AF_INET:
((struct sockaddr_in *)addr)->sin_port = port;
case AF_INET6:
((struct sockaddr_in6 *)addr)->sin6_port = port;
}
return 0;
}
/* set port in network byte order */
static inline int set_host_port(struct sockaddr_storage *addr, int port)
{
switch (addr->ss_family) {
case AF_INET:
((struct sockaddr_in *)addr)->sin_port = htons(port);
case AF_INET6:
((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
}
return 0;
}
/* Return true if IPv4 address is part of the network */
extern int in_net_ipv4(struct in_addr *addr, struct in_addr *mask, struct in_addr *net);
/* Return true if IPv6 address is part of the network */
extern int in_net_ipv6(struct in6_addr *addr, struct in6_addr *mask, struct in6_addr *net);
/* Map IPv4 adress on IPv6 address, as specified in RFC 3513. */
extern void v4tov6(struct in6_addr *sin6_addr, struct in_addr *sin_addr);
/* Map IPv6 adress on IPv4 address, as specified in RFC 3513.
* Return true if conversion is possible and false otherwise.
*/
extern int v6tov4(struct in_addr *sin_addr, struct in6_addr *sin6_addr);
char *human_time(int t, short hz_div);
extern const char *monthname[];
/* date2str_log: write a date in the format :
* sprintf(str, "%02d/%s/%04d:%02d:%02d:%02d.%03d",
* tm.tm_mday, monthname[tm.tm_mon], tm.tm_year+1900,
* tm.tm_hour, tm.tm_min, tm.tm_sec, (int)date.tv_usec/1000);
*
* without using sprintf. return a pointer to the last char written (\0) or
* NULL if there isn't enough space.
*/
char *date2str_log(char *dest, struct tm *tm, struct timeval *date, size_t size);
/* gmt2str_log: write a date in the format :
* "%02d/%s/%04d:%02d:%02d:%02d +0000" without using snprintf
* return a pointer to the last char written (\0) or
* NULL if there isn't enough space.
*/
char *gmt2str_log(char *dst, struct tm *tm, size_t size);
/* Dynamically allocates a string of the proper length to hold the formatted
* output. NULL is returned on error. The caller is responsible for freeing the
* memory area using free(). The resulting string is returned in <out> if the
* pointer is not NULL. A previous version of <out> might be used to build the
* new string, and it will be freed before returning if it is not NULL, which
* makes it possible to build complex strings from iterative calls without
* having to care about freeing intermediate values, as in the example below :
*
* memprintf(&err, "invalid argument: '%s'", arg);
* ...
* memprintf(&err, "parser said : <%s>\n", *err);
* ...
* free(*err);
*
* This means that <err> must be initialized to NULL before first invocation.
* The return value also holds the allocated string, which eases error checking
* and immediate consumption. If the output pointer is not used, NULL must be
* passed instead and it will be ignored. The returned message will then also
* be NULL so that the caller does not have to bother with freeing anything.
*
* It is also convenient to use it without any free except the last one :
* err = NULL;
* if (!fct1(err)) report(*err);
* if (!fct2(err)) report(*err);
* if (!fct3(err)) report(*err);
* free(*err);
*/
char *memprintf(char **out, const char *format, ...)
__attribute__ ((format(printf, 2, 3)));
/* Used to add <level> spaces before each line of <out>, unless there is only one line.
* The input argument is automatically freed and reassigned. The result will have to be
* freed by the caller.
* Example of use :
* parse(cmd, &err); (callee: memprintf(&err, ...))
* fprintf(stderr, "Parser said: %s\n", indent_error(&err));
* free(err);
*/
char *indent_msg(char **out, int level);
/* debugging macro to emit messages using write() on fd #-1 so that strace sees
* them.
*/
#define fddebug(msg...) do { char *_m = NULL; memprintf(&_m, ##msg); if (_m) write(-1, _m, strlen(_m)); free(_m); } while (0)
#endif /* _COMMON_STANDARD_H */