xref: /freebsd/lib/libc/stdtime/strptime.3 (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
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26.\" $FreeBSD$
27.\" "
28.Dd May 8, 1997
29.Dt STRPTIME 3
30.Os
31.Sh NAME
32.Nm strptime
33.Nd parse date and time string
34.Sh LIBRARY
35.Lb libc
36.Sh SYNOPSIS
37.In time.h
38.Ft char *
39.Fo strptime
40.Fa "const char * restrict buf"
41.Fa "const char * restrict format"
42.Fa "struct tm * restrict timeptr"
43.Fc
44.Sh DESCRIPTION
45The
46.Fn strptime
47function parses the string in the buffer
48.Fa buf
49according to the string pointed to by
50.Fa format ,
51and fills in the elements of the structure pointed to by
52.Fa timeptr .
53The resulting values will be relative to the local time zone.
54Thus, it can be considered the reverse operation of
55.Xr strftime 3 .
56.Pp
57The
58.Fa format
59string consists of zero or more conversion specifications and
60ordinary characters.
61All ordinary characters are matched exactly with the buffer, where
62white space in the format string will match any amount of white space
63in the buffer.
64All conversion specifications are identical to those described in
65.Xr strftime 3 .
66.Pp
67Two-digit year values, including formats
68.Fa %y
69and
70.Fa \&%D ,
71are now interpreted as beginning at 1969 per POSIX requirements.
72Years 69-00 are interpreted in the 20th century (1969-2000), years
7301-68 in the 21st century (2001-2068).
74.Sh RETURN VALUES
75Upon successful completion,
76.Fn strptime
77returns the pointer to the first character in
78.Fa buf
79that has not been required to satisfy the specified conversions in
80.Fa format .
81It returns
82.Dv NULL
83if one of the conversions failed.
84.Sh SEE ALSO
85.Xr date 1 ,
86.Xr scanf 3 ,
87.Xr strftime 3
88.Sh AUTHORS
89The
90.Fn strptime
91function has been contributed by Powerdog Industries.
92.Pp
93This man page was written by
94.An J\(:org Wunsch .
95.Sh HISTORY
96The
97.Fn strptime
98function appeared in
99.Fx 3.0 .
100.Sh BUGS
101Both the
102.Fa %e
103and
104.Fa %l
105format specifiers may incorrectly scan one too many digits
106if the intended values comprise only a single digit
107and that digit is followed immediately by another digit.
108Both specifiers accept zero-padded values,
109even though they are both defined as taking unpadded values.
110.Pp
111The
112.Fa %p
113format specifier has no effect unless it is parsed
114.Em after
115hour-related specifiers.
116Specifying
117.Fa %l
118without
119.Fa %p
120will produce undefined results.
121Note that 12AM
122(ante meridiem)
123is taken as midnight
124and 12PM
125(post meridiem)
126is taken as noon.
127.Pp
128The
129.Fa %U
130and
131.Fa %W
132format specifiers accept any value within the range 00 to 53
133without validating against other values supplied (like month
134or day of the year, for example).
135.Pp
136The
137.Fa %Z
138format specifier only accepts time zone abbreviations of the local time zone,
139or the value "GMT".
140This limitation is because of ambiguity due to of the over loading of time
141zone abbreviations.  One such example is
142.Fa EST
143which is both Eastern Standard Time and Eastern Australia Summer Time.
144