UNIX — универсальная среда программирования - Керниган Брайан Уилсон

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Автор Керниган Брайан Уилсон

int argc;

char *argv[];

{

struct stat buf;

char *name, *getlogin();

int lastsize = 0;

progname = argv[0];

if ((name = getlogin()) == NULL)

error("can't get login name", (char*)0);

if (chdir(maildir) == -1)

error("can't cd to %s", maildir);

for (;;) {

if (stat(name, &buf) == -1) /* no mailbox */

buf.st_size = 0;

if (buf.st_size > lastsize)

fprintf(stderr, "\nYou have mail\007\n");

lastsize = buf.st_size;

sleep(60);

}

#include "error.c"

3.8.13

checkmail.sh

# checkmail: watch mailbox for growth

PATH=/bin:/usr/bin

MAIL=/usr/spool/mail/`getname` # system dependent

t=${1-60}

x="`ls -l $MAIL`"

while :

do

y="`ls -l $MAIL`"

echo $x $y x="$y"

sleep $t

done | awk '$4 < $12 { print "You have mail" }'

3.8.14

cp.c

/* cp: minimal version */

#include <stdio.h>

#define PERMS 0644 /* RW for owner, R for group, others */

char *progname;

main(argc, argv) /* cp: copy f1 to f2 */

int argc;

char *argv[];

{

char buf[BUFSIZ];

progname = argv[0];

if (argc != 3)

error("Usage: %s from to", progname);

if ((f1 = open(argv[1], 0)) == -1)

error("can't open %s", argv[1]);

if ((f2 = creat(argv[2] , PERMS)) == -1)

error("can't create %s", argv[2]);

while ((n = read(f1, buf, BUFSIZ)) > 0)

if (write(f2, buf, n) != n)

error("write error", (char*)0);

exit(0);

}

#include "error.c"

3.8.15

doctype

# doctype: synthesize proper command line for troff

echo -n "cat $* | "

egrep -h '^\.(EQ|TS|\[|PS|IS|PP)' $* |

sort -u | awk '

/^\.PP/ { ms++ }

/^\.EQ/ { eqn++ }

/^\.TS/ { tbl++ }

/^\.PS/ { pic++ }

/^\.IS/ { ideal++ }

/^\.\[/ { refer++ }

END {

if (refer > 0) printf "refer | "

if (pic > 0) printf "pic | "

if (ideal > 0) printf "ideal | "

if (tbl > 0) printf "tbl | "

if (eqn > 0) printf "eqn | "

printf "troff "

if (ms > 0) printf "-ms"

printf "\n"

}'

3.8.16

double

awk '

FILENAME != prevfile { # new file

NR = 1 # reset line number

prevfile = FILENAME

}

NF > 0 {

if ($1 == lastword)

printf "double %s, file %s, line %d\n" ,$1,FILENAME,NR

for (i = 2; i <= NF; i++)

if ($i == $(i-1))

printf "double %s, file %s, line %d\n" ,$i, FILENAME ,NR

if (NF > 0)

lastword = $NF

}' $*

3.8.17

efopen.c

FILE *efopen(file, mode) /* fopen file, die if can't */

char *file, *mode;

{

FILE *fp, *fopen();

extern char *progname;

if ((fp = fopen(file, mode)) != NULL)