mktime 和 strftime 函数

力哥丶

1. [root@localhost ~]# awk 'BEGIN{a=mktime("2001 02 02 12 12 12");print a}'
   
2. 981087132
   
3. 
   
4. 
   
5. [root@localhost ~]# awk 'BEGIN{a=mktime("2001 02 02 12 12 12");print strftime("%c",a)}'
   
6. Fri 02 Feb 2001 12:12:12 PM CST

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mktime设置的时间格式输出的结果怎么是981087132？ 这个是1970 01 01 所相差的时间么？
           这个函数不是用来设置显示的时间格式么？

必须要配合strftime？

jason680

回复 1# 力哥丶

$ man awk
GAWK(1)                        Utility Commands                        GAWK(1)

NAME
       gawk - pattern scanning and processing language

SYNOPSIS
       gawk [ POSIX or GNU style options ] -f program-file [ -- ] file ...
       gawk [ POSIX or GNU style options ] [ -- ] program-text file ...

       pgawk [ POSIX or GNU style options ] -f program-file [ -- ] file ...
       pgawk [ POSIX or GNU style options ] [ -- ] program-text file ...

  ...
   Time Functions
       Since one of the primary uses of AWK programs is processing  log  files
       that  contain time stamp information, gawk provides the following func‐
       tions for obtaining time stamps and formatting them.

       mktime(datespec)
                 Turns datespec into a time stamp of the same form as returned
                 by  systime().   The datespec is a string of the form YYYY MM
                 DD HH MM SS[ DST].  The contents of the  string  are  six  or
                 seven numbers representing respectively the full year includ‐
                 ing century, the month from 1 to 12, the  day  of  the  month
                 from  1  to  31, the hour of the day from 0 to 23, the minute
                 from 0 to 59, and the second from 0 to 60,  and  an  optional
                 daylight  saving  flag.  The values of these numbers need not
                 be within the ranges specified; for example, an  hour  of  -1
                 means 1 hour before midnight.  The origin-zero Gregorian cal‐
                 endar is assumed, with year 0 preceding year 1  and  year  -1
                 preceding  year  0.   The  time is assumed to be in the local
                 timezone.  If the daylight saving flag is positive, the  time
                 is  assumed  to be daylight saving time; if zero, the time is
                 assumed to be standard time; and if negative  (the  default),
                 mktime()  attempts  to determine whether daylight saving time
                 is in effect for the specified time.  If  datespec  does  not
                 contain  enough  elements  or if the resulting time is out of
                 range, mktime() returns -1.

       strftime([format [, timestamp[, utc-flag]]])
                 Formats timestamp according to the specification  in  format.
                 If  utc-flag  is  present  and  is  non-zero or non-null, the
                 result is in UTC, otherwise the result is in local time.  The
                 timestamp  should  be  of  the  same form as returned by sys‐
                 time().  If timestamp is missing, the current time of day  is
                 used.   If  format is missing, a default format equivalent to
                 the output of date(1) is used.  See the specification for the
                 strftime() function in ANSI C for the format conversions that
                 are guaranteed to be available.

       systime() Returns the current time of day  as  the  number  of  seconds
                 since the Epoch (1970-01-01 00:00:00 UTC on POSIX systems).
   

力哥丶

回复 2# jason680


    返回systime（） 那这个就相当于1970-01-01到现在的时间差了？