UNIX — универсальная среда программирования - Керниган Брайан Уилсон

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Автор Керниган Брайан Уилсон

3.8.4

backwards

# backwards: print input in backward line order

awk ' { line[NR] = $0 }

END { for (i = NR; i > 0; i--) print line[i] } ' $*

3.8.5

badpick.c

pick(s) /* offer choice of s */

char *s;

{

fprintf("%s? ", s);

if (ttyin() == 'y')

printf("%s\n", s);

}

3.8.6

bundle

# bundle: group files into distribution package

echo '# To unbundle, sh this file'

for i

do

echo "echo $i 1>&2"

echo "cat >$i <<'End of $i'"

cat $i

echo "End of $i"

done

3.8.7

cal

# cal: nicer interface to /usr/bin/cal

case $# in

0) set `date`; m=$2; y=$6 ;; # no args: use today

1) m=$1; set `date`; y=$6 ;; #1 arg: use this year

*) m=$1; y=$2 ;; #2 args: month and year

esac

case $m in

jan*|Jan*) m=1 ;;

feb*|Feb*) m=2 ;;

mar*|Mar*) m=3 ;;

apr*|Apr*) m=4 ;;

may*|May*) m=5 ;;

jun*|Jun*) m=6 ;;

jul*|Jul*) m=7 ;;

aug*|Aug*) m=8 ;;

sep*|Sep*) m=9 ;;

oct*|Oct*) m=10 ;;

nov*|Nov*) m=11 ;;

dec*|Dec*) m=12 ;;

[1-9]|10|11|12) ;; # numeric month

*) y=$m; m="" ;; # plain year

esac

/usr/bin/cal $m $y # run the real one

3.8.8

calendar1

# calendar: version 1 -- today only

awk <$HOME/calendar '

BEGIN { split("'"`date`"'", date) }

$1 == date[2] && $2 == date[3]

' | mail $NAME

3.8.9

calendar2

# calendar: version 2 -- today only, no quotes

(date; cat $HOME/calendar) |

awk '

NR == 1 { mon = $2; day = $3 } # set the date

NR > 1 && $1 == mon && $2 == day # print calendar lines

' | mail $NAME

3.8.10

calendar3

# calendar: version 3 -- today and tomorrow

awk <$HOME/calendar '

BEGIN {

x = "Jan 31 Feb 28 Mar 31 Apr 30 May 31 Jun 30 " \

"Jul 31 Aug 31 Sep 30 Oct 31 Nov 30 Dec 31 Jan 31"

split(x, data)

for (i = 1; i < 24; i += 2) {

days[data[i]] = data[i+1]

nextmon[data[i]] = data[i+2]

}

split("'"`date`"'", date)

mon1 = date[2]; day1 = date[3]

mon2 = mon1; day2 = day1 + 1

if (day1 >= days[mon1]) {

day2 = 1

mon2 = nextmon[mon1]

}

$1 == mon1 && $2 == day1 || $1 == mon2 && $2 == day2

' | mail $NAME

3.8.11

cat0.c

/* cat: minimal version */

#define SIZE 512 /* arbitrary */

main() {

char buf[SIZE];

int n;

while ((n = read(0, buf, sizeof buf)) > 0)

write(1, buf, n);

exit(0);

}

3.8.12

checkmail.c

/* checkmail: watch user's mailbox */

#include <stdio.h>

#include <sys/types.h>

#include <sys/stat.h>

char *progname;

char *maildir = "/usr/spool/mail"; /* system dependent */

main(argc, argv)