Utilities

Detailed Description

This is a small collection of general purpose utilities.

Macros
#define	DEBUG_TEST   0
#define	TIME_RFC3339_STRLEN   31
#define	debug()
#define	debug_print(str)
#define	debug_printf(fmt, ...)
#define	ARRAY_COUNT(a)   sizeof(a) / sizeof(a[0])
#define	CHECK_MALLOC(a)
#define	INCREMENT(a)   a += 1
#define	DECREMENT(a)   a -= 1

Functions
int	utl_ip_port_from_ss (char *ip, size_t ip_len, uint16_t *port, struct sockaddr_storage *ss)
double	utl_diff_timespec_as_double (const struct timespec *t1, const struct timespec *t2)
void	utl_diff_timespec (struct timespec *dst, const struct timespec *t1, const struct timespec *t2)
void	char_to_lc (char *c)
void	str_to_lc (uint8_t *str, size_t str_len)
bool	str_is_numeric (uint8_t *str, size_t str_len)
int	str_to_unsigned_long (unsigned long *dst, char *str)
int	str_to_bool (bool *dst, char *str)
int	parse_csv_to_ul_array (size_t *ul_array, size_t ul_array_len, char *str)
int	sockaddr_storage_to_string (char *buf, size_t buf_len, struct sockaddr_storage *ss)
int	utl_readall (int fd, size_t size, void **buf, char *err, size_t err_len)
int	utl_writeall (int fd, void *buf, size_t buf_len, char *err, size_t err_len)
int	utl_timespec_to_rfc3339nano (struct timespec *ts, char *buf)
void	utl_clock_gettime_rt_fatal (struct timespec *tp)

Macro Definition Documentation

ARRAY_COUNT

#define ARRAY_COUNT

(

a

)

sizeof(a) / sizeof(a[0])

Macro to calculate array size.

CHECK_MALLOC

#define CHECK_MALLOC

(

a

)

Value:

    do { \
    if((a) == NULL) { \
        assert(0); \
    } } while (0)

Macro to check result of memory allocation, asserts on memory allocation failure.

debug

#define debug

(

)

Value:

        do { if (DEBUG_TEST) fprintf(stderr, "%s:%d:%s(): \n", __FILE__, \
                                __LINE__, __func__); } while (0)

Macro to print out debug message if DEBUG is set at compile time. This prints out filename, line in file, and function it was called in.

debug_print

#define debug_print

(

str

)

Value:

        do { if (DEBUG_TEST) fprintf(stderr, "%s:%d:%s(): " str "\n", __FILE__, \
                                __LINE__, __func__); } while (0)

Macro to print out debug message if DEBUG is set at compile time. This prints out everything macro debug does plus a string passed in as argument.

Parameters

str	String to print out.

debug_printf

#define debug_printf	(		fmt,
			...
	)

Value:

        do { if (DEBUG_TEST) fprintf(stderr, "%s:%d:%s(): " fmt "\n", __FILE__, \
                                __LINE__, __func__, __VA_ARGS__); } while (0)

Macro to print out debug message if DEBUG is set at compile time. This prints out everything macro debug does plus a string passed in as argument. String can be formatted.

Note

Only use this function to output a formatted string as "fmt" + variable list is REQUIRED. To output string with no format use debug_print macro.

Parameters

fmt	String format followed by variable list.

DEBUG_TEST

#define DEBUG_TEST   0

Constant enables printing of debug messages to stderr. Otherwise if not set the compiler optimizes out (removes) all of the debug message code.

DECREMENT

#define DECREMENT

(

a

)

a -= 1

Macro to decrement a variable by one.

INCREMENT

#define INCREMENT

(

a

)

a += 1

Macro to increment a variable by one.

TIME_RFC3339_STRLEN

#define TIME_RFC3339_STRLEN   31

Length of buffer needed to store time as rfc399nano formatted string

Function Documentation

char_to_lc()

void char_to_lc ( char *  c )

inline

Convert ascii character to lower case. If character is not alphabet [A-Z] or is already in lower case, this is a no-op.

Parameters

c	Character to convert to lower case.

Here is the caller graph for this function:

parse_csv_to_ul_array()

int parse_csv_to_ul_array	(	size_t *	ul_array,
		size_t	ul_array_len,
		char *	str
	)

Parse comma separated values into array of unsigend long integers.

strtok() is not used as it skips empty entries (i.e. ',,').

Parameters

ul_array	Array to parse entries into.
ul_array_len	Number of slots in array.
str	String to parse CSV from.

Returns

0 on success, otherwise an error occurred.

Here is the call graph for this function:

Here is the caller graph for this function:

sockaddr_storage_to_string()

int sockaddr_storage_to_string	(	char *	buf,
		size_t	buf_len,
		struct sockaddr_storage *	ss
	)

Convert IPv4 or IPv6 addresses and port from binary to text form as "ip:port".

Parameters

buf	Buffer to store string into.
buf_len	Length of buffer, must be large enough to account for IPv6, ":", port (5 characters), plus a '\0' string terminator.
ss	struct_sockaddr to extract IP and port from.

Returns

0 on success, otherwise error occurred. -1 indicates that buf_len was too small, any other value is errno set by inet_ntop().

Here is the call graph for this function:

str_is_numeric()

bool str_is_numeric	(	uint8_t *	str,
		size_t	str_len
	)

Check if ascii string is solely composed of numeric [0-9] characters.

Parameters

str	String to check.
str_len	Length of string.

Returns

Returns tue if ascii string is numeric, otherwise returns false.

Here is the caller graph for this function:

str_to_bool()

int str_to_bool	(	bool *	dst,
		char *	str
	)

Convert strings "true" and "false" to boolean and store result in dst. Input strings can be a mix of upper and lower case characters.

Parameters

dst	Destination to store value to
str	String to convert to bool.

Returns

0 on success, otherwise an error occurred, meaning string does not represent "true" or "false".

Here is the call graph for this function:

Here is the caller graph for this function:

str_to_lc()

void str_to_lc	(	uint8_t *	str,
		size_t	str_len
	)

Convert string ascii characters to lower case.

Parameters

str	String to convert to all lower case ASCII.
str_len	Length of string.

Here is the call graph for this function:

Here is the caller graph for this function:

str_to_unsigned_long()

int str_to_unsigned_long	(	unsigned long *	dst,
		char *	str
	)

Convert string to unsigned long and store result in dst. This function only handles base 10 numbers.

Parameters

dst	Destination to store value to
str	String to convert to unsigned long.

Returns

0 on success, otherwise an error occurred.

Here is the caller graph for this function:

utl_clock_gettime_rt_fatal()

void utl_clock_gettime_rt_fatal

(

struct timespec *

tp

)

Get current time from clock CLOCK_REALTIME (see man -3 time) and store it in tp.

Note

This function is fatal on error. Error can only occur if there is something majorly wrong with underlying OS. Regardless, not being able to get current time impacts critical application function.

Parameters

tp	Where to store current time.

Here is the caller graph for this function:

utl_diff_timespec()

void utl_diff_timespec	(	struct timespec *	dst,
		const struct timespec *	t1,
		const struct timespec *	t2
	)

Get a difference between two timespec stuctures t1 - t2.

Note

t1 MUST be larger than t2.

Parameters

dst	Where to store result.
t1	Time to subtract from.
t2	Time to subtract.

Here is the caller graph for this function:

utl_diff_timespec_as_double()

double utl_diff_timespec_as_double	(	const struct timespec *	t1,
		const struct timespec *	t2
	)

Get a difference between two timespec stuctures t1 - t2 and return the result as type double.

Parameters

t1	Time to subtract from.
t2	Time to subtract.

Returns

Time difference as double.

Here is the caller graph for this function:

utl_ip_port_from_ss()

int utl_ip_port_from_ss	(	char *	ip,
		size_t	ip_len,
		uint16_t *	port,
		struct sockaddr_storage *	ss
	)

From sockaddr_storage extract IP and port into strings.

Parameters

ip	Buffer where to store IP address.
ip_len	Length of space available in ip buffer.
port	Buffer where to store TCP/UDP port.
ss	sockaddr_storage to extract IP and port from.

Returns

0 on success, otherwise error occurred.

Here is the caller graph for this function:

utl_readall()

int utl_readall	(	int	fd,
		size_t	size,
		void **	buf,
		char *	err,
		size_t	err_len
	)

Read size specified from file descriptor into memory.

Note

Per Linux manual read() will return at most 0x7ffff000 (2,147,479,552) bytes, hence a need for this function to keep reading until the full size specified is read into memory buffer.

Parameters

fd	Open file descriptor to read from, seek position MUST be at the begining of the file.
size	Number of bytes to read in.
buf	Pointer where to store buffer data is read into.
err	Buffer where to store error string if error occurred. Error string is guaranteed to end with '\0' so i.e. a followup call to strlen() is a valid action.
err_len	Size of err buffer.

Returns

On success returns 0, otherwise error occurred in which case *buf is set to NULL and error message is populated.

Here is the caller graph for this function:

utl_timespec_to_rfc3339nano()

int utl_timespec_to_rfc3339nano	(	struct timespec *	ts,
		char *	buf
	)

Store time in ts as string in GMT rfc3339nano format.

Parameters

ts	Time to store as string.
buf	Buffer to store times string at. This buffer MUST have minimum length of TIME_RFC3339_STRLEN.

Here is the caller graph for this function:

utl_writeall()

int utl_writeall	(	int	fd,
		void *	buf,
		size_t	buf_len,
		char *	err,
		size_t	err_len
	)

Write data from buffer to open file descriptor fd until all data was written.

Parameters

fd	Open file descriptor to write to.
buf	Buffer to write data from.
buf_len	Length of data in buff to write.
err	Buffer where to store error message if one is encountered.
err_len	Size of err buffer available to store error message.

Returns

On success returns 0. Otherwise error occurred and error message was populated. If error occurred it is possible that only part of the data was written.

Here is the caller graph for this function: