NAME¶
parse_time,
print_time_table,
unparse_time,
unparse_time_approx, —
parse and unparse time intervals
LIBRARY¶
The roken library (libroken, -lroken)
SYNOPSIS¶
#include
<parse_time.h>
int
parse_time(
const
char *timespec,
const char
*def_unit);
void
print_time_table(
FILE
*f);
size_t
unparse_time(
int
seconds,
char
*buf,
size_t
len);
size_t
unparse_time_approx(
int
seconds,
char
*buf,
size_t
len);
DESCRIPTION¶
The
parse_time() function converts the period
of time specified into a number of seconds. The
timespec can be any number of ⟨number
unit⟩ pairs separated by comma and whitespace. The number can be
negative. Numbers without explicit units are taken as being
def_unit.
The
unparse_time() and
unparse_time_approx() do the opposite of
parse_time(), that is they take a number of
seconds and express that as human readable strings.
unparse_time produces an exact time, while
unparse_time_approx restricts the result to
include only one unit.
print_time_table() prints a descriptive list
of available units on the passed file descriptor.
The possible units include:
Units names can be arbitrarily abbreviated (as long as they are unique).
RETURN VALUES¶
parse_time() returns the number of seconds
that represents the expression in
timespec or
-1 on error.
unparse_time() and
unparse_time_approx() return the number of
characters written to
buf. if the return
value is greater than or equal to the
len
argument, the string was too short and some of the printed characters were
discarded.
EXAMPLES¶
#include <stdio.h>
#include <parse_time.h>
int
main(int argc, char **argv)
{
int i;
int result;
char buf[128];
print_time_table(stdout);
for (i = 1; i < argc; i++) {
result = parse_time(argv[i], "second");
if(result == -1) {
fprintf(stderr, "%s: parse error\n", argv[i]);
continue;
}
printf("--\n");
printf("parse_time = %d\n", result);
unparse_time(result, buf, sizeof(buf));
printf("unparse_time = %s\n", buf);
unparse_time_approx(result, buf, sizeof(buf));
printf("unparse_time_approx = %s\n", buf);
}
return 0;
}
$ ./a.out "1 minute 30 seconds" "90 s" "1 y -1 s"
1 year = 365 days
1 month = 30 days
1 week = 7 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 second
--
parse_time = 90
unparse_time = 1 minute 30 seconds
unparse_time_approx = 1 minute
--
parse_time = 90
unparse_time = 1 minute 30 seconds
unparse_time_approx = 1 minute
--
parse_time = 31535999
unparse_time = 12 months 4 days 23 hours 59 minutes 59 seconds
unparse_time_approx = 12 months
BUGS¶
Since
parse_time() returns -1 on error there
is no way to parse "minus one second". Currently "s" at
the end of units is ignored. This is a hack for English plural forms. If these
functions are ever localised, this scheme will have to change.
