Брайан Керниган - UNIX — универсальная среда программирования

PATH=/bin:/usr/bin

VERSION=0

while test "$1" != ""

do

 case "$1" in

 -i) INPUT=$2; shift ;;

 -o) OUTPUT=$2; shift ;;

 -[0-9]) VERSION=$1 ;;

 -*) echo "get: Unknown argument $i" 1>&2; exit 1 ;;

 *) case "$OUTPUT" in

  "") OUTPUT=$1 ;;

  *) INPUT=$1.H ;;

  esac

 esac

 shift

done

OUTPUT=${OUTPUT?"Usage: get [-o outfile] [-i file.H] file"}

INPUT=${INPUT-$OUTPUT.H}

test -r $INPUT || { echo "get: no file $INPUT" 1>&2; exit 1; }

trap 'rm -f /tmp/get.[ab]$$; exit 1' 1 2 15

# split into current version and editing commands

sed <$INPUT -n '1,/^@@@/w /tmp/get.a'$$'

/^@@@/,$w /tmp/get.b'$$

# perform the edits

awk </tmp/get.b$$ '

 /^@@@/ { count++ }

 !/^@@@/ && count > 0 && count <= - '$VERSION'

 END { print "$d"; print "w", "'$OUTPUT'" }

' | ed - /tmp/get.a$$

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

3.8.25 get.с

get(fd, pos, buf, n) /* read n bytes from position pos */

 int fd, n;

 long pos;

 char *buf;

{

 if (lseek(fd, pos, 0) == -1) /* get to pos */

  return -1;

 return read(fd, buf, n);

}

3.8.26 getname

who am i | sed 's/ .*//'

3.8.27 idiff.c

/* idiff: interactive diff */

#include <stdio.h>

#include <ctype.h>

char *progname;

#define HUGE 10000 /* large number of lines */

main(argc, argv)

 int argc;

 char *argv[];

{

 FILE *fin, *fout, *f1, *f2, *efopen();

 char buf[BUFSIZ], *mktemp();

 char *diffout = "idiff.XXXXXX";

 progname = argv[0];

 if (argc != 3) {

  fprintf(stderr, "Usage: idiff file1 file2n");

  exit(1);

 }

 f1 = efopen(argv[1], "r");

 f2 = efopen(argv[2], "r");

 fout = efopen("idiff.out", "w");

 mktemp(diffout);

 sprintf(buf, "diff %s %s >%s", argv[1], argv[2], diffout);

 system(buf);

 fin = efopen(diffout, "r");

 idiff(f1, f2, fin, fout); unlink(diffout);

 printf("%s output in file idiff.outn", progname);

 exit(0);

}

idiff(f1, f2, fin, fout) /* process diffs */

 FILE *f1, *f2, *fin, *fout;

{

 char *tempfile = "idiff.XXXXXX";

 char buf[BUFSIZ], buf2[BUFSIZ], *mktemp();

 FILE *ft, *efopen();

 int cmd, n, from1, to1, from2, to2, nf1, nf2;

 mktemp(tempfile);

 nf1 = nf2 = 0;

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

  parse(buf, &from1, &to1, &cmd, &from2, &to2);

  n = to1-from1 + to2-from2 + 1; /* #lines from diff */

  if (cmd == 'c')

   n += 2;

  else if (cmd == 'a')

   from1++;

  else if (cmd == 'd')

   from2++;

  printf("%s", buf);

  while (n-- > 0) {

   fgets(buf, sizeof buf, fin);

   printf("%s", buf);

  }

  do {

   printf("? ");

   fflush(stdout);

   fgets(buf, sizeof buf, stdin);

   switch (buf[0]) {

   case '>':

    nskip(f1, to1-nf1);

    ncopy(f2, to2-nf2, fout);

    break;

   case '<':

    nskip(f2, to2-nf2);

    ncopy(f1, to1-nf1, fout);

    break;

   case 'e':

    ncopy(f1, from1-1-nf1, fout);

    nskip(f2, from2-1-nf2);

    ft = efopen(tempfile, "w");

    ncopy(f1, to1+1-from1, ft);

    fprintf(ft, "--- n");

    ncopy(f2, to2+1-from2, ft);

    fclose(ft);

    sprintf(buf2, "ed %s", tempfile);

    system(buf2);

    ft = efopen(tempfile, "r");

    ncopy(ft, HUGE, fout);

    fclose(ft);

    break;

   case '!':

    system(buf+1);

    printf("!n");

    break;

   default:

    printf("< or > or e or !n");

    break;

   }

  } while (buf[0]!= '<' && buf[0]!= '>' && buf[0]! = 'e');

  nf1 = to1;

  nf2 = to2;

 }

 ncopy(f1, HUGE, fout); /* can fail on very long files */

 unlink(tempfile);

}

parse(s, pfrom1, pto1, pcmd, pfrom2, pto2)

 char *s;

 int *pcmd, *pfrom1, *pto1, *pfrom2, *pto2;

{

#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"

3.8.28 makefile

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

3.8.29 newer

# newer f: list files newer than f

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

3.8.30 news1

# 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

3.8.31 news2

# 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

3.8.32 news3

# 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

3.8.33 nohup

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

3.8.34 older

# older f: list files older than f

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

3.8.35 overwrite1

# 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

3.8.36 overwrite2

# 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

3.8.37 overwrite3

# 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

3.8.38 p1.c

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

#include <stdio.h>