UNIX — универсальная среда программирования

 {
  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 }
  /</ { $1 = "out: "; 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'