diff options
Diffstat (limited to 'lib/libc/time/ctime.3')
| -rw-r--r-- | lib/libc/time/ctime.3 | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/lib/libc/time/ctime.3 b/lib/libc/time/ctime.3 index 5fe445196ab..d7bc31615f2 100644 --- a/lib/libc/time/ctime.3 +++ b/lib/libc/time/ctime.3 @@ -1,4 +1,4 @@ -.\" $OpenBSD: ctime.3,v 1.28 2003/07/07 15:38:38 jmc Exp $ +.\" $OpenBSD: ctime.3,v 1.29 2004/10/18 22:33:43 millert Exp $ .\" .\" .Dd February 16, 1999 @@ -59,12 +59,19 @@ pointed to by representing the time in seconds since 00:00:00 UTC, 1970-01-01, and returns a pointer to a -26-character string -of the form +string of the form .Pp .Dl Thu Nov 24 18:22:48 1986\en .Pp -All the fields have constant width. +Years requiring fewer than four characters are padded with trailing spaces. +For years longer than four characters, the string is of the form +.Pp +.Dl Thu Nov 24 18:22:48\ \ \ \ \ 81986\en +.Pp +with five spaces before the year. +This unusual format is designed to make it less likely that older +software that expects exactly 26 bytes of output will mistakenly output +misleading values for out-of-range years. .Pp The .Fn ctime_r @@ -130,10 +137,9 @@ the reentrant version is not required to set .Fn asctime converts a time value contained in a .Li tm -structure to a 26-character string, +structure to a string, as shown in the above example, -and returns a pointer -to the string. +and returns a pointer to the string. .Fn asctime_r uses the buffer pointed to by .Fa buf @@ -285,6 +291,20 @@ will also be overwritten at the next call (and by calls to .Fn tzset ) . .Pp +.Fn asctime +and +.Fn ctime +behave strangely for years before 1000 or after 9999. +The 1989 and 1999 editions of the C Standard say +that years from \-99 through 999 are converted without +extra spaces, but this conflicts with longstanding +tradition and with this implementation. +Traditional implementations of these two functions are +restricted to years in the range 1900 through 2099. +To avoid this portability mess, new programs should use +.Fn strftime +instead. +.Pp The default system time zone may be set by running .Dq Li zic -l timezone as the superuser. @@ -292,6 +312,6 @@ as the superuser. Avoid using out-of-range values with .Fn mktime when setting up lunch with promptness sticklers in Riyadh. -.\" based on @(#)newctime.3 7.14 +.\" based on @(#)newctime.3 7.16 .\" This file is in the public domain, so clarified as of .\" 2003-02-14 by Arthur David Olson (arthur_david_olson@nih.gov). |