UTIL(3) Library Functions Manual UTIL(3)

UtilSome misc. helper functions that don't need their own headers.

#include <Util.h>

unsigned long

unsigned long
UtilLastModified(char *);

UtilMkdir(const char *, const mode_t);


UtilParseBytes(char *);

UtilGetDelim(char **, size_t *, int, FILE *);

UtilGetLine(char **, size_t *, FILE *);

This header holds a number of random functions related to strings, time, and other tasks that don't require a full API, just one or two functions. For the most part, the functions here are entirely standalone, depending only on POSIX functions, however there are a few that specifically utilize Telodendria APIs. Those are noted.

() gets the current time in milliseconds since the Unix epoch. This uses gettimeofday(2) and time_t, and converts it to a single number, which is then returned to the caller. A note on the 2038 problem: as long as sizeof(long) >= 8, that is, as long as the long datatype is 64 bits or more, which it is on all modern 64-bit Unix-like operating systems, then everything should be fine. Expect Telodendria on 32 bit machines to break in 2038. I didn't want to try to hack together some system to store larger numbers than the architecture supports. We can always re-evaluate things over the next decade.

() behaves just like the system call mkdir(2), but it creates any intermediate directories if necessary, unlike mkdir(2).

() sleeps the calling thread for the given number of milliseconds. It occurred to me that POSIX does not specify a super friendly way to sleep, so this is a wrapper around the POSIX nanosleep(2) designed to make its usage much, much simpler.

() uses stat(2) to get the last modified time of the given file. This is used primarily for caching file data.

() is a highly specialized function used in parsing the configuration file. It takes in a string which is supposed to represent a number of bytes. It must consist of an integer, followed by an optional suffix of k, K, m, M, g, or G, indicating the value is kilobytes, megabytes, or gigabytes.

() and () work identically to the POSIX equivalents, documented in getdelim(3), except it assumes pointers were allocated using the Memory API, and it uses the Memory API itself to reallocate necessary pointers.

UtilServerTs() and UtilLastModified() return timestamps in the form of milliseconds since the Unix epoch as an unsigned long. The Matrix specification requires timestamps be in milliseconds, so these functions are designed to make that easy and convenient.

UtilMkdir() returns 0 on success, and -1 on failure, just like mkdir(2). It also sets errno as appropriate.

UtilSleepMillis() returns the result of calling nanosleep(2).

UtilParseBytes() returns a number of bytes, or 0 if there was an error parsing the byte string.

UtilGetDelim() and UtilGetLine() return the same value as their POSIX equivalents, documented in getdelim(3).

February 15, 2023 Telodendria Project