isisutils.c File Reference

ISIS client utility functions. More...

#include "isisclient.h"

Functions
void	LeftStr (char *substr, char *str, int nchar)
	Extract the n left-most characters from a given string.
void	RightStr (char *substr, char *str, int nchar)
	Extract the n right-most characters from a given string.
void	MidStr (char *substr, char *str, int start, int nchar)
	Extract n characters starting in the middle of a string.
void	SubStr (char *substr, char *str, int first, int last)
	Extracts a substring from inside a larger string.
void	UpperCase (char *str)
	Convert all characters in a string up uppercase.
void	GetArg (char *cmdstr, int argnum, char *argstr)
	Extract the n-th argument from a command string with arguments separated by spaces.
char *	UTCDateTag (void)
	Create a CCYYMMDD date tag string.
char *	UTCDate (void)
	Return the UTC date in ISO8601 format.
char *	UTCTime (void)
	Return the UTC Time in ISO8601 format.
char *	ISODate (void)
	Return the UTC date and time in ISO8601 format.
char *	GetFineTime (void)
	Return UTC time with microsecond precision.
double	SysTimestamp (void)
	Return elapsed time since UTC 1970 Jan 1 with microsecond precision.
int	MilliSleep (long msec)
	Pause execution for a certain number of msec.

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Detailed Description

ISIS client utility functions.

A suite of utility functions that most ISIS client applications will find useful. These include functions for string handling (something stock C is not well-equipped with), an dfunctions for getting time and date information, including date/time in ISO8601 format.

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Function Documentation

void LeftStr (  char *  substr, char *  str, int  nchar )

Extract the n left-most characters from a given string. Parameters: substr  Substring to extract str  Original string nchar  Number of characters to extract

void RightStr (  char *  substr, char *  str, int  nchar )

Extract the n right-most characters from a given string. Parameters: substr  Substring to extract str  Original string nchar  Number of characters to extract

void MidStr (  char *  substr, char *  str, int  start, int  nchar )

Extract n characters starting in the middle of a string. Parameters: substr  Substring to extract str  Original string start  Starting character in str nchar  Number of characters to extract See also: SubStr()

void SubStr (  char *  substr, char *  str, int  first, int  last )

Extracts a substring from inside a larger string. Parameters: substr  Substring to extract str  Original string first  First character in str to extract last  Last character in str to extract See also: MidStr()

void UpperCase (  char *  str  )

Convert all characters in a string up uppercase. Parameters: str  String to be converted to uppercase

void GetArg (  char *  cmdstr, int  argnum, char *  argstr )

Extract the n-th argument from a command string with arguments separated by spaces. Parameters: cmdstr  Command string with space-separated arguments argnum  Number of the argument to extract (1..n) argstr  Argument string to return Returns the n-th argument in a command string that contains a series of command-line arguments separated by spaces. Provides a very simple command parsing capability. The command looks like cmd arg1 arg2 .. argN With the command verb itself being considerd argument "0". Returns a null string in argstr if argnum is out of range.

char* UTCDateTag (  void   )

Create a CCYYMMDD date tag string. Reads the system timeclock and returns the UTC date in CCYYMMDD format. This is a hyphen-free variant on the standard ISO8601 format date specification. See also: UTCDate(), ISODate()

char* UTCDate (  void   )

Return the UTC date in ISO8601 format. Reads the system clock and returns the UTC date in ISO8601-compliant CCYY-MM-DD format, where CCYY is the year (century and year), MM is the month number (01..12), and DD is the day of the month (01..28/29/30/31). See also: UTCDateTag(), ISODate()

char* UTCTime (  void   )

Return the UTC Time in ISO8601 format. Reads the system clock and returns the UTC time in ISO8601-compliant time to the nearest second in hh:mm:ss format. See also: GetFineTime(), ISODate()

char* ISODate (  void   )

Return the UTC date and time in ISO8601 format. Reads the system clock and returns the UTC date and time in full ISO8601-compliant date/time format: CCYY-MM-DDThh:mm:ss where: CCYY-MM-DD is the UTC date hh:mm:ss is the UTC time to the nearest second We omit the zone specification described by ISO8601 since this only reads UTC time. See also: UTCDate(), UTCTime(), UTCDateTag()

char* GetFineTime (  void   )

Return UTC time with microsecond precision. Reads the system's UTC time clock and returns a pointer to a string with the fine-grained UTC time in hh:mm:ss.ssssss format. Based on gf_time() from Stevens, W.R., 1998, Unix Network Programming, Vol 2, Prentice Hall, Figure 15.6, but I make a string, and extract time to microsec instead of msec. Note: It returns microsecond precision, accuracy is quite another matter... See also: UTCTime(), ISODate()

double SysTimestamp (  void   )

Return elapsed time since UTC 1970 Jan 1 with microsecond precision. Reads the system's time clock and returns a double-precision value with the time in seconds and microseconds since UTC 1970 January 1. The primary use of this function is to create a fine-grained numerical timestamp for the system, but other uses are possible. Note: It returns microsecond precision, accuracy is quite another matter... See also: GetFineTime()

int MilliSleep (  long  msec  )

Pause execution for a certain number of msec. Parameters: msec  - time to sleep in milliseconds Returns: 0 if successful, -1 if there were problems. errno says what is bothering it. Acts as a convenience function for using nanosleep(), the POSIX.1b conformal way of suspending a process for a certain time. nanosleep() is a replacement for the obsolete usleep() when a sleep interval more fine-grained than sleep() is required. sleep() only allows intervals in integer seconds, which is not short enough for some applications. For most of what we do, msec are the appropriate interval, and nanosleep() can be somewhat involved to setup. This function encapsulates the nasty setup for calling nanosleep() as a convenience for users. See "man 2 nanosleep" for details on the nanosleep() function.

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