 28.3.    echo
          echo 

\                      .

\                    BACKSPACE ( ).

\                      NEWLINE.

\f                    FORMFEED ( ).

\n                     NEWLINE ( ).

\r                    RETURN.

\t                     .

\v                     .

\\                    .

\nnn                     ASCII- .   
 ,  echo    .

 safedit    ,     -
  vi:

$ cat safedit

t!/bin/bash
t UNIX/WORLD, IV:11

PATH=/bin:/usr/bin
script=$(basename $0)
case $t in

0)

vi
exit 0

I I

1)

if [ ! -f "$1" ]
then

vi "$1"
exit 0
fi

if [ ! -r "$1" -o ! -w "$1" ]
then

echo "$script:     $1" 1>&2
exit 1
else

editfile=$l
fi

if [ ! -w "." ]
then

echo "$script:    " \

"   " 1>&2
exit 1
fi

892                                                  VI. 