UNIX — страница 115 из 115

3.8.1 addup1

awk '{ s += $'$1' }
 END { print s }'

3.8.2. addup2

awk '
 BEGIN { n = '$1' }
 { for (i = 1; i <= n; i++)
  sum[i] += $i
 }
 END { for (i = 1; i <= n; i++) {
  printf "%6g ", sum[i]
  total += sum[i]
  }
 printf "; total = %6g\n", total
}'

3.8.3 backup

push -v panther $* /usr/bwk/eff/Code

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 
#include 
#include 

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

main(argc, argv)
 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 
#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)
  return fp;
 fprintf (stderr, "%s: can't open file %s mode %s\n",
  progname, file, mode);
 exit(1);
}

3.8.18 error.c

error(s1, s2) /* print error message and die */
 char *s1, *s2;
{
 extern int errno, sys_nerr;
 extern char *sys_errlist[], *progname;

 if (progname)
  fprintf(stderr, "%s: ", progname);
 fprintf(stderr, s1, s2);
 if (errno > 0 && errno < sys_nerr)
  fprintf (stderr, " (%s)", sys_errlist[errno]);
 fprintf(stderr, "\n");
 exit(1);
}

3.8.19 field1

awk '{ print $'$1' }'

3.8.20 field2

awk "{ print \$$1 }"

3.8.21 fold

# fold: fold long lines
sed 's/\(->/ /g' $* | # convert tabs to spaces
awk '
 BEGIN {
  N = 80                   # folds at column 80
  for (i = 1; i <= N; i++) # make a string of blanks
   blanks = blanks " "
 }
 { if ((n = length($0)) <= N)
  print
  else {
   for (i = 1; n > N; n -= N) {
    printf "%s\\\n", substr($0, i ,N)
    i += N;
   }
   printf "%s%s\n", substr(blanks, 1, N-n), substr($0, i)
  }
 } '

3.8.22 frequent

cat $* |
tr -sc A-Za-z '\012' |
sort |
uniq -с |
sort -n |
tail |
5

3.8.23 frequent2

sed 's/[ \(->][ \(->]*/\
/g' $* | sort | uniq -с | sort -nr | sed 10q

3.8.24 get

# get: extract file from history

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 
 /^@@@/ { 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 
#include 

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 file2\n");
  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.out\n", 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 
#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"

3.8.39 p2.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"

3.8.40 p3.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"

3.8.41 p4.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];

 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] = '\0';
   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 

3.8.43 pick.c

/* pick: offer choice on each argument */

#include 
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] = '\0'; /* 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("%s\n", 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 $i sed "s@$left@$right@g" $i
done

3.8.48 signaltest.c

#include 
#include 
#include 

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 {
   if (errno == EINTR) {
    errno = 0;
    printf("interrupt side %d\n", n);
   } else {
    printf("true end of file %d\n", n);
   }
  }
 }
}

onintr() {
 signal(SIGINT, onintr);
 printf("interrupt\n");
}

3.8.49 spname.c

/* spname: return correctly spelled filename */
/*
 * spname(oldname, newname) char *oldname, *newname;
 * returns -1 if no reasonable match to oldname,
 * 0 if exact match,
 * 1 if corrected.
 * stores corrected name in newname.
 */

#include 
#include 

spname(oldname, newname)
 char *oldname, *newname;
{
 char *p, guess[DIRSIZ+1], best[DIRSIZ+1];
 char *new = newname, *old = oldname;

 for (;;) {
  while (*old == '/') /* skip slashes */
   *new++ = *old++;
  *new = '\0';
  if (*old == '\0') /* exact or corrected */
   return strcmp(oldname, newname) != 0;
  p = guess; /* copy next component into guess */
  for ( ; *old != '/' && *old != '\0'; old++)
   if (p < guess+DIRSIZ)
  *p++ = *old;
  *p = '\0';
  if (mindist(newname, guess, best) >= 3)
   return -1; /* hopeless */
  for (p = best; *new = *p++; ) /* add to end */
   new++; /* of newname */
 }
}

mindist(dir, guess, best) /* search dir for guess */
 char *dir, *guess, *best;
{
 /* set best, return distance 0..3 */
 int d, nd, fd;
 struct {
  ino_t ino;
  char name[DIRSIZ+1]; /* 1 more than in dir.h */
 } nbuf;

 nbuf.name[DIRSIZ] = '\0'; /* +1 for terminal '\0' */
 if (dir[0] == '\0') /* current directory */
  dir = ".";
 d = 3; /* minimum distance */
 if ((fd=open(dir, 0)) == -1)
  return d;
 while (read(fd, (char*)&nbuf, sizeof(struct direct)) > 0)
  if (nbuf.ino) {
   nd = spdist(nbuf.name, guess);
   if (nd <= d && nd != 3) {
    strcpy(best, nbuf.name);
    d = nd;
    if (d == 0) /* exact match */
    break;
   }
  }
 close(fd);
 return d;
}

/* spdist: return distance between two names */
/*
 * very rough spelling metric:
 * 0 if the strings are identical
 * 1 if two chars are transposed
 * 2 if one char wrong, added or deleted
 * 3 otherwise
 */
#define EQ(s,t) (strcmp(s,t) == 0)

spdist(s, t)
 char *s, *t;
{
 while (*s++ == *t)
  if (*t++ == '\0')
   return 0; /* exact match */
 if (*--s) {
  if (*t) {
   if (s[1] && t[1] && *s == t[1] && *t == s[1] && EQ(s+2, t+2))
    return 1; /* transposition */
   if (EQ(s+1, t+1))
    return 2; /* 1 char mismatch */
  }
  if (EQ(s+1, t))
   return 2; /* extra character */
 }
 if (*t && EQ(s, t+1))
  return 2; /* missing character */
 return 3;
}

3.8.50 strindex.c

strindex(s, t) /* return index of t in s, -1 if none */
 char *s, *t;
{
 int i, n;

 n = strlen(t);
 for (i = 0; s[i] != '\0'; i++)
  if (strncmp(s+i, t, n) == 0)
   return i;
 return -1;
}

3.8.51 sv.c

/* sv: save new files */

#include 
#include 
#include 
#include 

char *progname;
main(argc, argv)
 int argc;
 char *argv[];
{
 int i;
 struct stat stbuf;
 char *dir = argv[argc-1];

 progname = argv[0];
 if (argc <= 2)
  error ("Usage: %s files... dir", progname);
 if (stat(dir, festbuf) == -1)
  error("can't access directory %s", dir);
 if ((stbuf.st_mode & S_IFMT) != S_IFDIR)
  error("%s is not a directory", dir);
 for (i = 1; i < argc-1; i++)
  sv(argv[i], dir);
 exit(0);
}

sv(file, dir) /* save file in dir */
 char *file, *dir;
{
 struct stat sti, sto;
 int fin, fout, n;
 char target[BUFSIZ], buf[BUFSIZ], *index();

 sprintf(target, "%s/%s", dir, file);
 if (index(file, '/') != NULL) /* strchr() in some systems */
  error("won't handle '/'s in %s", file);
 if (stat(file, &sti) == -1)
  error("can't stat %s", file);
 if (stat(target, &sto) == -1) /* target not present */
  sto.st_mtime = 0; /* so make it look old */
 if (sti.st_mtime < sto.st_mtime) /* target is newer */
  fprintf(stderr, "%s: %s not copied\n", progname, file);
 else if ((fin = open(file, 0)) == -1)
  error("can't open file %s", file);
 else if ((fout = creat(target, sti.st_mode)) == -1)
  error("can't create %s", target);
 while ((n = read(fin, buf, sizeof buf)) > 0)
  if (write(fout, buf, n) != n)
   error("error writing %s", target);
 close(fin);
 close(fout);
}

#include "error.c"

3.8.52 system1.c

#include 

system(s) /* run command line s */
 char *s;
{
 int status, pid, w, tty;
 int (*istat)(), (*qstat)();

 ...
 if ((pid = fork()) == 0) {
  ...
  execlp("sh", "sh", "-c", s, (char*)0);
  exit(127);
 }
 ...
 istat = signal(SIGINT, SIG_IGN);
 qstat = signal(SIGQUIT, SIG_IGN);
 while ((w = wait(&status)) != pid && w != -1)
  ;
 if (w == -1)
  status = -1;
 signal(SIGINT, istat);
 signal(SIGQUIT, qstat);
 return status;
}

3.8.53 system.c

/*
 * Safer version of system for interactive programs
 */

#include 
#include 

system(s) /* run command line s */
 char *s;
{
 int status, pid, w, tty;
 int (*istat)(), (*qstat)();
 extern char *progname;

 fflush(stdout);
 tty = open("/dev/tty", 2);
 if (tty == -1) {
  fprintf (stderr, "%s: can't open /dev/tty\n", progname);
  return -1;
 }
 if ((pid = fork()) == 0) {
  close(0);
  dup(tty);
  close(1);
  dup(tty);
  close(2);
  dup(tty);
  close(tty);
  execlp("sh", "sh", "-c", s, (char*)0);
  exit(127);
 }
 close(tty);
 istat = signal(SIGINT, SIG_IGN);
 qstat = signal(SIGQUIT, SIG_IGN);
 while ((w = wait(&status)) != pid && w != -1)
  ;
 if (w == -1)
  status = -1;
 signal(SIGINT, istat);
 signal(SIGQUIT, qstat);
 return status;
}

3.8.54 timeout.c

/* timeout: set time limit on a process */
#include 
#include 

int pid; /* child process id */
char *progname;

main(argc, argv)
 int argc;
 char *argv[];
{
 int sec = 10, status, onalarm();

 progname = argv[0];
 if (argc > 1 && argv[1][0] == '-') {
  sec = atoi(&argv[1][1]);
  argc--;
  argv++;
 }
 if (argc < 2)
  error("Usage: %s [-10] command", progname);
 if ((pid=fork()) == 0) {
  execvp(argv[1], &argv[1]);
  error("couldn't start %s", argv[1]);
 }
 signal(SIGALRM, onalarm);
 alarm(sec);
 if (wait(&status) == -1 || (status & 0177) != 0)
  error("%s killed", argv[1]);
 exit((status >> 8) & 0377);
}

onalarm() /* kill child when alarm arrives */
{
 kill(pid, SIGKILL);
}

#include "error.c"

3.8.55 toolong

length($0) > 72 { print "Line", NR, "too long:", substr($0,1,60) }

3.8.56 ttyin1.c

ttyin() /* process response from /dev/tty (version 1) */
{
 char buf[BUFSIZ];
 FILE *efopen();
 static FILE *tty = NULL;

 if (tty == NULL)
  tty = efopen("/dev/tty", "r");
 if (fgets(buf, BUFSIZ, tty) == NULL || buf[0] == 'q')
  exit(0);
 else /* ordinary line */
  return buf[0];
}

3.8.57 ttyin2.c

ttyin() /* process response from /dev/tty (version 2) */
{
 char buf[BUFSIZ];
 FILE *efopen();
 static FILE *tty = NULL;

 if (tty == NULL)
  tty = efopen("/dev/tty", "r");
 for (;;) {
  if (fgets(buf,BUFSIZ,tty) == NULL || buf[0] == 'q')
  exit(0);
  else if (buf[0] == '!') {
   system(buf+1); /* BUG here */
   printf("!\n");
  }
  else /* ordinary line */
   return buf[0];
 }
}

#include "system.c"

3.5.58 vis1.c

/* vis: make funny characters visible (version 1) */
#include 
#include 

main() {
 int c;

 while ((c = getchar()) != EOF)
  if (isascii(c) &&
   (isprint(c) || c=='\n' || c=='\t' || c==' '))
   putchar(c);
  else
   printf("\\%03o", c);
 exit(0);
}

3.5.59 vis2.c

/* vis: make funny characters visible (version 2) */
#include 
#include 

main(argc, argv)
 int argc;
 char *argv[];
{
 int с, strip = 0;

 if (argc > 1 && strcmp(argv[1] , "-s") == 0)
  strip = 1;
 while ((c = getchar()) != EOF) if (isascii(c) &&
  (isprint(c) || c=='\n' || c=='\t' || c==' '))
  putchar(c);
 else if (!strip)
  printf("\\%03o", c);
 exit(0);
}

3.8.60 vis3.c

/* vis: make funny characters visible (version 3) */
#include 
#include 

int strip = 0; /* 1 => discard special characters */

main(argc, argv)
 int argc;
 char *argv[];
{
 int i;
 FILE *fp;

 while (argc > 1 && argv[1][0] == '-') {
  switch (argv[1][1]) {
  case 's': /* -s: strip funny chars */
   strip = 1;
   break;
  default:
   fprintf(stderr, "%s: unknown arg %s\n",
    argv[0], argv[1]);
   exit(1);
  }
  argc--;
  argv++;
 }
 if (argc == 1)
  vis(stdin);
 for (i = 1; i < argc; i++)
  if ((fp=fopen(argv[i], "r")) == NULL) {
   fprintf(stderr, "%s: can't open %s\n",
    argv[0], argv[i]);
   exit(1);
  } else {
   vis(fp);
   fclose(fp);
  }
 exit(0);
}

vis(fp) /* make chars visible in FILE *fp */
 FILE *fp;
{
 int c;

 while ((c = getc(fp)) != EOF)
  if (isascii(c) &&
   (isprint(c) || c=='\n' || c=='\t' || c==' '))
   putchar(c);
  else if (!strip)
   printf("\\%03o", с);
}

3.8.61 waitfile.c

/* waitfile: wait until file stops changing */
#include 
#include 
#include 

char *progname;

main(argc, argv)
 int argc;
 char *argv[];
{
 int fd;
 struct stat stbuf;
 time_t old_time = 0;

 progname = argv[0];
 if (argc < 2)
  error("Usage: %s filename [cmd]", progname);
 if ((fd = open(argv[1], 0)) == -1)
  error("can't open %s", argv[1]);
 fstat(fd, &stbuf);
 while (stbuf.st_mtime != old_time) {
  old_time = stbuf.st_mtime;
  sleep(60);
  fstat(fd, &stbuf);
 }
 if (argc == 2) { /* copy file */
  execlp("cat", "cat", argv[1], (char*)0);
  error("can't execute cat %s", argv[1]);
 } else { /* run process */
  execvp(argv[2], &argv[2]);
  error("can't execute %s", argv[2]);
 }
 exit(0);
}

#include "error.c"

3.8.62 watchfor

# watchfor: watch for someone to log in

PATH=/bin:/usr/bin

case $# in
0) echo 'Usage: watchfor person' 1>&2; exit 1
esac

until who | egrep "$1"
do
 sleep 60
done

3.8.63 watchwho

# watchwho: watch who logs in and out

PATH=/bin:/usr/bin
new=/tmp/wwho1.$$
old=/tmp/wwho2.$$
> $old # create an empty file

while : # loop forever
do
 who >$new
 diff $old $new
 mv $new $old
 sleep 60
done | awk '/>/ { $1 = "in: "; print }
            /

3.8.64 which1

# which cmd: which cmd in PATH is executed, version 1

case $# in
0) echo 'Usage: which command' 1>&2; exit 2
esac
for i in `echo $PATH | sed 's/^:/.:/
                            s/::/:.:/g
                            s/:$/:./
                            s/:/ /g'`
do
 if test -f $i/$1 # use test -x if you can
 then
  echo $i/$1
  exit 0 # found it
 fi
done
exit 1 # not found

3.8.65 which1.H

# which cmd: which cmd in PATH is executed, version 1

case $# in
0) echo 'Usage: which command' 1>&2; exit 2
esac
for i in `echo $PATH | sed 's/^:/.:/
                            s/::/:.:/g
                            s/:$/:./
                            s/:/ /g'`
do
 if test -f $i/$1 # use test -x if you can
 then
  echo $i/$1
  exit 0 # found it
 fi
done
exit 1 # not found
@@@ Fri Oct 14 14:21:11 EDT 1983 original version

3.8.66 which2

# which cmd: which cmd in PATH is executed, final version

opath=$PATH PATH=/bin:/usr/bin

case $# in
0) echo 'Usage: which command' 1>&2; exit 2
esac
for i in `echo $opath | sed 's/^:/.:/
                             s/::/:.:/g
                             s/:$/:./
                             s/:/ /g'`
do
 if test -f $i/$1 # this is /bin/test
 then # or /usr/bin/test only
  echo $i/$1
  exit 0 # found it
 fi
done
exit 1 # not found

3.8.67 wordfreq

awk ' { for (i = 1; i <= NF; i++) num[$i]++ }
END {for (word in num) print word, num[word] }
' $*

3.8.68 zap1

# zap pattern: kill all processes matching pattern
# BUG in this version

PATH=/bin:/usr/bin

case $# in
0) echo 'Usage: zap pattern' 1>&2; exit 1
esac

kill `pick \`ps -ag | grep "$*"\` | awk '{print $1}'`

3.8.69 zap2

# zap pat: kill all processes matching pat
# final version

PATH=/bin:/usr/bin

IFS='
' # just a newline
case $1 in
"") echo 'Usage: zap [-2] pattern' 1>&2; exit 1 ;;
-*) SIG=$1; shift
esac

echo ' PID TTY TIME CMD'
kill $SIG `pick \`ps -ag | egrep "$*"|` | awk '{print $1}'`

3.8.70 zap.c

/* zap: interactive process killer */

#include 
#include 
char *progname; /* program name for error message */
char *ps = "ps -ag"; /* system dependent */

main(argc, argv)
 int argc;
 char *argv[];
{
 FILE *fin, *popen();
 char buf[BUFSIZ];
 int pid;

 progname = argv[0];
 if ((fin = popen(ps, "r")) == NULL) {
  fprintf (stderr, "%s: can't run %s\n", progname, ps);
  exit(1);
 }
 fgets(buf, sizeof buf, fin); /* get header line */
 fprintf (stderr, "%s", buf);
 while (fgets(buf, sizeof buf, fin) != NULL)
  if (argc == 1 || strindex(buf, argv[1]) >= 0) {
   buf[strlen(buf)-1] = '\0'; /* suppress \n */
   fprintf (stderr, "%s? ", buf);
   if (ttyin() == 'y') {
    sscanf(buf, "%d", &pid);
    kill(pid, SIGKILL);
   }
  }
 exit(0);
}
#include "ttyin2.c"
#include "strindex.c"
#include "efopen.c"