UNIX — универсальная среда программирования - Брайан Керниган

#include <stdio.h>

#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] = '';

   fputs(buf, stdout);

   fflush(stdout);

   ttyin();

   lines = 0;

  }

}

#include "ttyin1.c"

#include "efopen.c"

3.8.39 p2.c

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

#include <stdio.h>

#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] = '';

   fputs(buf, stdout);

   fflush(stdout);

   ttyin();

   lines = 0;

  }

}

#include "ttyin2.c"

#include "efopen.c"

3.8.40 p3.c

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

#include <stdio.h>

#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] = '';

   fputs(buf, stdout);

   fflush(stdout);

   ttyin();

   lines = 0;

  }

}

#include "ttyin2.c"

#include "efopen.c"

3.8.41 p4.c

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

#include <stdio.h>

#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];

 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++)

   switch (spname(argv[i], buf)) {

   case -1: /* no match possible */

    fp = efopen(argv[i], "r");

    break;

   case 1: /* corrected */

    fprintf (stderr, ""%s"? ", buf);

    if (ttyin() == 'n')

     break;

    argv[i] = buf;

    /* fall through... */

   case 0: /* exact match */

    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] = '';

   fputs(buf, stdout);

   fflush(stdout);

   ttyin();

   lines = 0;

  }

}

#include "ttyin2.c"

#include "efopen.c"

#include "spname.c"

3.8.42 pick1

# pick: select arguments

PATH=/bin:/usr/bin

for i # for each argument

do

 echo -n "$i? " >/dev/tty

 read response

 case $response in

 y*) echo $i ;;

 q*) break

 esac

done </dev/tty

3.8.43 pick.c

/* pick: offer choice on each argument */

#include <stdio.h>

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

main(argc, argv)

 int argc;

 char *argv[];

{

 int i;

 char buf[BUFSIZ];

 progname = argv[0];

 if (argc == 2 && strcmp(argv[1], "-") == 0) /* pick - */

  while (fgets(buf, sizeof buf, stdin) != NULL) {

   buf[strlen(buf)-1] = ''; /* drop newline */

   pick(buf);

  }

 for (i = 1; i < argc; i++)

  pick(argv[i]);

 exit(0);

}

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

 char *s;

{

 fprintf(stderr, "%s? ", s);

 if (ttyin() == 'y')

  printf("%sn", s);

}

#include "ttyin2.c"

#include "efopen.c"

3.8.44 prpages

# prpages: compute number of pages that pr will print

wc $* |

awk '!/ total$/ { n += int(($1+55) / 56) }

 END { print n }'

3.8.45 put

# put: install file into history

PATH=/bin:/usr/bin

case $# in

1) HIST=$1.H ;;

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

esac

if test ! -r $1

then

 echo "put: can't open $1" 1>&2

 exit 1

fi

trap 'rm -f /tmp/put.[ab]$$; exit 1 12 15

echo -n 'Summary: '

read Summary

if get -o /tmp/put.a$$ $1 # previous version

then # merge pieces

 cp $1 /tmp/put.b$$ # current version

 echo `getname` `date` $Summary" >>/tmp/put.b$$

 diff -e $1 /tmp/put.a$$ >>/tmp/put.b$$ # latest diffs

 sed -n '/^@@@/,$р' <$HIST >>/tmp/put.b$$ # old diffs

 overwrite $HIST cat /tmp/put.b$$ # put it back

else # make a new one

 echo "put: creating $HIST"

 cp $1 $HIST

 echo "@@@ `getname` `date` $Summary" >>$HIST

fi

rm -f /tmp/put.[ab]$$

3.8.46 readslow.c

/* readslow: keep reading, waiting for more */

#define SIZE 512 /* arbitrary */

main() {

 char buf[SIZE];

 int n;

 for (;;) {

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

   write(1, buf, n);

  sleep(10);

 }

}

3.8.47 replace

# replace: replace str1 in files with str2, in place

PATH=/bin:/usr/bin

case $# in

0|1|2) echo 'Usage: replace str1 str2 files' 1>&2; exit 1

esac

left="$1"; right="$2"; shift; shift

for i

do

 overwrite $i sed "[email protected][email protected][email protected]" $i

done

3.8.48 signaltest.c

#include <stdio.h>

#include <signal.h>

#include <errno.h>

extern int errno;

main() {

 int с, n;

 char buf[100];

 int onintr();

 signal(SIGINT, onintr);

 for (;;) {

  n = read(0, buf, 100);

  if (n > 0)

   printf(buf);

  else {