1PARSE_TIME(3) BSD Library Functions Manual PARSE_TIME(3)
2
4 parse_time, print_time_table, unparse_time, unparse_time_approx, — parse
5 and unparse time intervals
6
8 The roken library (libroken, -lroken)
9
11 #include <parse_time.h>
12 int
14 parse_time(const char *timespec, const char *def_unit);
15 void
17 print_time_table(FILE *f);
18 size_t
20 unparse_time(int seconds, char *buf, size_t len);
21 size_t
23 unparse_time_approx(int seconds, char *buf, size_t len);
24
26 The parse_time() function converts the period of time specified into a
27 number of seconds. The timespec can be any number of ⟨number unit⟩ pairs
28 separated by comma and whitespace. The number can be negative. Numbers
29 without explicit units are taken as being def_unit.
30 The unparse_time() and unparse_time_approx() do the opposite of
32 parse_time(), that is they take a number of seconds and express that as
33 human readable strings. unparse_time produces an exact time, while
34 unparse_time_approx restricts the result to include only one unit.
35 print_time_table() prints a descriptive list of available units on the
37 passed file descriptor.
38 The possible units include:
40 second, s
41 minute, m
42 hour, h
43 day
44 week seven days
45 month 30 days
46 year 365 days
47 Units names can be arbitrarily abbreviated (as long as they are unique).
49
51 parse_time() returns the number of seconds that represents the expression
52 in timespec or -1 on error. unparse_time() and unparse_time_approx()
53 return the number of characters written to buf. if the return value is
54 greater than or equal to the len argument, the string was too short and
55 some of the printed characters were discarded.
56
58 #include <stdio.h>
59 #include <parse_time.h>
60 int
62 main(int argc, char **argv)
63 {
64 int i;
65 int result;
66 char buf[128];
67 print_time_table(stdout);
68 for (i = 1; i < argc; i++) {
69 result = parse_time(argv[i], "second");
70 if(result == -1) {
71 fprintf(stderr, "%s: parse error\n", argv[i]);
72 continue;
73 }
74 printf("--\n");
75 printf("parse_time = %d\n", result);
76 unparse_time(result, buf, sizeof(buf));
77 printf("unparse_time = %s\n", buf);
78 unparse_time_approx(result, buf, sizeof(buf));
79 printf("unparse_time_approx = %s\n", buf);
80 }
81 return 0;
82 }
83 $ ./a.out "1 minute 30 seconds" "90 s" "1 y -1 s"
85 1 year = 365 days
86 1 month = 30 days
87 1 week = 7 days
88 1 day = 24 hours
89 1 hour = 60 minutes
90 1 minute = 60 seconds
91 1 second
92 --
93 parse_time = 90
94 unparse_time = 1 minute 30 seconds
95 unparse_time_approx = 1 minute
96 --
97 parse_time = 90
98 unparse_time = 1 minute 30 seconds
99 unparse_time_approx = 1 minute
100 --
101 parse_time = 31535999
102 unparse_time = 12 months 4 days 23 hours 59 minutes 59 seconds
103 unparse_time_approx = 12 months
104
106 Since parse_time() returns -1 on error there is no way to parse "minus
107 one second". Currently "s" at the end of units is ignored. This is a
108 hack for English plural forms. If these functions are ever localised,
109 this scheme will have to change.
110HEIMDAL November 17, 2013 HEIMDAL