Rewriting UNIX cal(1)

Question

Hello,

Today I was testing out SRFI 19 and wrote a simple version of the UNIX cal(1) command.

Here's a version in R6RS Scheme which runs in Ikarus, Ypsilon, and Larceny. A few example runs.

Schemers: How would you write it? Use your favorite implementation.

Ruby and Python: I'm guessing that y'all have elegant date and time libraries. I'm sure you can put the Schemers to shame. ;-) Let's see what ya got.

I'd also like to see Haskell and golfed versions.

Is there a Stack Overflow tag for re-implementations of UNIX commands? :-)

Ed

Answer 1

Python - 61 chars

Here's a whole program that takes two arguments, month and year

import sys,calendar as C
C.prmonth(*map(int,sys.argv[:0:-1]))

58 chars if we are allowed to reverse the order of the arguments

import sys,calendar as C
C.prmonth(*map(int,sys.argv[1:]))

Sample run

$ python cal.py 3 2012
     March 2012
Mo Tu We Th Fr Sa Su
          1  2  3  4
 5  6  7  8  9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31

Python calendar module

>>> import calendar as c
>>> c.prmonth(2010,3)
     March 2010
Mo Tu We Th Fr Sa Su
 1  2  3  4  5  6  7
 8  9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31

>>> c.prcal(2012)
                                  2012

      January                   February                   March
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                   1             1  2  3  4  5                1  2  3  4
 2  3  4  5  6  7  8       6  7  8  9 10 11 12       5  6  7  8  9 10 11
 9 10 11 12 13 14 15      13 14 15 16 17 18 19      12 13 14 15 16 17 18
16 17 18 19 20 21 22      20 21 22 23 24 25 26      19 20 21 22 23 24 25
23 24 25 26 27 28 29      27 28 29                  26 27 28 29 30 31
30 31

       April                      May                       June
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                   1          1  2  3  4  5  6                   1  2  3
 2  3  4  5  6  7  8       7  8  9 10 11 12 13       4  5  6  7  8  9 10
 9 10 11 12 13 14 15      14 15 16 17 18 19 20      11 12 13 14 15 16 17
16 17 18 19 20 21 22      21 22 23 24 25 26 27      18 19 20 21 22 23 24
23 24 25 26 27 28 29      28 29 30 31               25 26 27 28 29 30
30

        July                     August                  September
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                   1             1  2  3  4  5                      1  2
 2  3  4  5  6  7  8       6  7  8  9 10 11 12       3  4  5  6  7  8  9
 9 10 11 12 13 14 15      13 14 15 16 17 18 19      10 11 12 13 14 15 16
16 17 18 19 20 21 22      20 21 22 23 24 25 26      17 18 19 20 21 22 23
23 24 25 26 27 28 29      27 28 29 30 31            24 25 26 27 28 29 30
30 31

      October                   November                  December
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
 1  2  3  4  5  6  7                1  2  3  4                      1  2
 8  9 10 11 12 13 14       5  6  7  8  9 10 11       3  4  5  6  7  8  9
15 16 17 18 19 20 21      12 13 14 15 16 17 18      10 11 12 13 14 15 16
22 23 24 25 26 27 28      19 20 21 22 23 24 25      17 18 19 20 21 22 23
29 30 31                  26 27 28 29 30            24 25 26 27 28 29 30
                                                    31