Shell Programming and Scripting

#!/usr/bin/env bash

# @(#) s3       Demonstrate display of days in month: "working", not weekend.

D=dateutils.dseq
# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C $D date grep

pl " First day of current month:"
date --date=today +%Y-%m-01

pl " Day 30 days in the future:"
date --date="now + 30 days" +%F

# Get list of working days from first of month.
$D -s "ss" $( date --date=today +%Y-%m-01 ) "$( date --date="now + 30 days" +%F )" -f "%F %a" > f1

pl " Sample of output:"
head -8 f1

pl " Select days 2,4,7:"
sed -n -e '2p' -e '4p' -e '7p' f1 |
tee f2

pl " Test if today is in the 3-day list:"
today=$( date +%F )
pe " today is $today"

if grep "$today" f2 >/dev/null
then
  pe " YES, touch the file now."
else
  pe " Today is NOT day 2,4,7, skipping touch."
fi

exit 0

$ ./s3

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 3.16.0-4-amd64, x86_64
Distribution        : Debian 8.4 (jessie) 
bash GNU bash 4.3.30
dateutils.dseq dseq 0.3.1
date (GNU coreutils) 8.23
grep (GNU grep) 2.20

-----
 First day of current month:
2016-06-01

-----
 Day 30 days in the future:
2016-07-09

-----
 Sample of output:
2016-06-01 Wed
2016-06-02 Thu
2016-06-03 Fri
2016-06-06 Mon
2016-06-07 Tue
2016-06-08 Wed
2016-06-09 Thu
2016-06-10 Fri

-----
 Select days 2,4,7:
2016-06-02 Thu
2016-06-06 Mon
2016-06-09 Thu

-----
 Test if today is in the 3-day list:
 today is 2016-06-09
 YES, touch the file now.

+ date '--date=now + 30 days' +%F
2016-07-09
++ date --date=today +%Y-%m-01
++ date '--date=now + 30 days' +%F
+ dateutils.dseq -s ss 2016-06-01 2016-07-09 -f '%F %a'
./ra_test.sh: line 27: dateutils.dseq: command not found
+ pl ' Sample of output:'
+ pe
+ printf '\n'

apt-get install date-utils