Брайан Керниган - UNIX — универсальная среда программирования

{

#define a2i(p) while (isdigit(*s)) \

p = 10*(p) + *s++ - '0'

*pfrom1 = *pto1 = *pfrom2 = *pto2 = 0;

a2i(*pfrom1);

if (*s == ',') {

s++;

a2i(*pto1);

} else

*pto1 = *pfrom1;

*pcmd = *s++;

a2i(*pfrom2);

if (*s == ',') {

s++;

a2i(*pto2);

} else

*pto2 = *pfrom2;

}

nskip(fin, n) /* skip n lines of file fin */

FILE *fin;

{

char buf[BUFSIZ];

while (n-- > 0)

fgets(buf, sizeof buf, fin);

}

ncopy(fin, n, fout) /* copy n lines from fin to fout */

FILE *fin, *fout;

{

char buf[BUFSIZ];

while (n-- > 0) {

if (fgets(buf, sizeof buf, fin) == NULL)

return;

fputs(buf, fout);

}

}

#include "efopen.c"

files: files.o files1.o directory.o

cc files.o files1.o directory.o -o files

p0: p0.c ttyin0.c

cc p0.c ttyin0.c

clean:

rm -f *.o a.out

# newer f: list files newer than f

ls -t | sed '/^'$1'$/q'

# news: print news files, version 1

HOME=. # debugging only

cd . # place holder for /usr/news

for i in `ls -t * $HOME/.news_time`

do

case $i in

*/.news_time) break ;;

*) echo news: $i

esac

done

touch $HOME/.news_time

# news: print news files, version 2

HOME=. # debugging only

cd . # place holder for /usr/news

IFS='

' # just a newline

for i in `ls -t * $HOME/.news_time 2>&1`

do

case $i in

*' not found') ;;

*/.news_time) break ;;

*) echo news: $i ;;

esac

done

touch $HOME/.news_time

# news: print news files, final version

PATH=/bin:/usr/bin

IFS='

' # just a newline

cd /usr/news

for i in `ls -t * $HOME/.news_time 2>&1`

do

IFS=' '

case $i in

*' not found') ;;

*/.news_time) break ;;

*) set X`ls -l $i`

echo "

$i: ($3) $5 $6 $7

"

cat $i

esac

done

touch $HOME/.news_time

trap "" 1 15

if test -t 2>&1

then

echo "Sending output to 'nohup.out'"

exec nice -5 $* >>nohup.out 2>&1

else

exec nice -5 $* 2>&1

fi

# older f: list files older than f

ls -tr | sed '/^'$!'$/q'

# overwrite: copy standard input to output after EOF

# version 1. BUG here

PATH=/bin:/usr/bin

case $# in

1) ;;

*) echo 'Usage: overwrite file' 1>&2; exit 2

esac

new=/tmp/overwr.$$

trap 'rm -f $new; exit 1' 1 2 15

cat >$new # collect the input

cp $new $1 # overwrite the input file

rm -f $new

# overwrite: copy standard input to output after EOF

# version 2. BUG here too

PATH=/bin:/usr/bin

case $# in

1) ;;

*) echo 'Usage: overwrite file' 1>&2; exit 2

esac

new=/tmp/overwr1.$$

old=/tmp/overwr2.$$

trap 'rm -f $new $old; exit 1' 1 2 15

cat >$new # collect the input

cp $1 $old # save original file

trap '' 1 2 15 # we are committed; ignore signals

cp $new $1 # overwrite the input file

rm -f $new $old

# overwrite: copy standard input to output after EOF

# final version

opath=$PATH

PATH=/bin:/usr/bin

case $# in

0|1) echo 'Usage: overwrite file cmd [args]' 1>&2; exit 2

esac

file=$1; shift

new=/tmp/overwr1.$$; old=/tmp/overwr2.$$

trap 'rm -f $new $old; exit 1' 1 2 15 # clean up files

if PATH=$opath >$new # collect input

then

cp $file $old # save original file

trap '' 1 2 15 # we are committed; ignore signals

cp $new $file

else

echo "overwrite: $1 failed, $file unchanged" 1>&2

exit 1

fi

rm -f $new $old

/* p: print input in chunks (version 1) */

#include

#define PAGESIZE 22

char *progname; /* program name for error message */

main(argc, argv)

int argc;

char *argv[];

{

int i;

FILE *fp, *efopen();

progname = argv[0];

if (argc == 1)

print(stdin, PAGESIZE);

else

for (i = 1; i < argc; i++) {

fp = efopen(argv[i], "r");

print(fp, PAGESIZE);

fclose(fp);

}

exit(0);

}

print(fp, pagesize) /* print fp in pagesize chunks */

FILE *fp;

int pagesize;

{

static int lines = 0; /* number of lines so far */

char buf[BUFSIZ];

while (fgets(buf, sizeof buf, fp) != NULL)

if (++lines < pagesize)

fputs(buf, stdout);

else {

buf[strlen(buf)-1] = '\0';

fputs(buf, stdout);

fflush(stdout);

ttyin();

lines = 0;

}

}

#include "ttyin1.c"

#include "efopen.c"

/* p: print input in chunks (version 2) */

#include

#define PAGESIZE 22

char *progname; /* program name for error message */

main(argc, argv)

int argc;

char *argv[];

{

FILE *fp, *efopen();

int i, pagesize = PAGESIZE;

progname = argv[0];

if (argc > 1 && argv[1][0] == '-') {

pagesize = atoi(&argv[1][1]);

argc--;

argv++;

}

if (argc == 1)

print(stdin, pagesize);

for (i = 1; i < argc; i++) {

fp = efopen(argv[i], "r");

print(fp, pagesize);

fclose(fp);

}

exit(0);

}

print(fp, pagesize) /* print fp in pagesize chunks */

FILE *fp;

int pagesize;

{

static int lines = 0; /* number of lines so far */

char buf[BUFSIZ];

while (fgets(buf, sizeof buf, fp) != NULL)

if (++lines < pagesize)

fputs(buf, stdout);

else {

buf[strlen(buf)-1] = '\0';

fputs(buf, stdout);

fflush(stdout);

ttyin();

lines = 0;

}

}

#include "ttyin2.c"

#include "efopen.c"

/* p: print input in chunks (version 3) */

#include

#define PAGESIZE 22

char *progname; /* program name for error message */

main(argc, argv)

int argc;

char *argv[];

{

FILE *fp, *efopen();

int i, pagesize = PAGESIZE;

char *p, *getenv();

progname = argv[0];

if ((p=getenv("PAGESIZE")) != NULL)

pagesize = atoi(p);

if (argc > 1 && argv[1][0] == '-') {

pagesize = atoi(&argv[1][1]);

argc--;

argv++;

}

if (argc == 1)

print(stdin, pagesize);

else

for (i = 1; i < argc; i++) {

fp = efopen(argv[i], "r");

print(fp, pagesize);

fclose(fp);

}

exit(0);

}

print(fp, pagesize) /* print fp in pagesize chunks */

FILE *fp;

int pagesize;

{

static int lines = 0; /* number of lines so far */

char buf[BUFSIZ];

while (fgets(buf, sizeof buf, fp) != NULL)

if (++lines < pagesize)

fputs(buf, stdout);

else {

buf[strlen(buf)-1] = '\0';

fputs(buf, stdout);

fflush(stdout);

ttyin();

lines = 0;

}

}

#include "ttyin2.c"

#include "efopen.c"

/* p: print input in chunks (version 4) */

#include

#define PAGESIZE 22

char *progname; /* program name for error message */

main(argc, argv)

int argc;

char *argv[];

{

FILE *fp, *efopen();

int i, pagesize = PAGESIZE;

char *p, *getenv(), buf[BUFSIZ];