UNIX for Beginners Questions & Answers

read -p "Enter 3 numbers: " num1 num2 num3;

read

Last login: Thu Dec 12 13:15:18 on ttys000
AMIGA:amiga~> bash --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin18)
Copyright (C) 2007 Free Software Foundation, Inc.
AMIGA:amiga~> 
AMIGA:amiga~> 
AMIGA:amiga~> help read
read: read [-ers] [-u fd] [-t timeout] [-p prompt] [-a array] [-n nchars] [-d delim] [name ...]
    One line is read from the standard input, or from file descriptor FD if the
    -u option is supplied, and the first word is assigned to the first NAME,
    the second word to the second NAME, and so on, with leftover words assigned
    to the last NAME.  Only the characters found in $IFS are recognized as word
    delimiters.  If no NAMEs are supplied, the line read is stored in the REPLY
    variable.  If the -r option is given, this signifies `raw' input, and
    backslash escaping is disabled.  The -d option causes read to continue
    until the first character of DELIM is read, rather than newline.  If the -p
    option is supplied, the string PROMPT is output without a trailing newline
    before attempting to read.  If -a is supplied, the words read are assigned
    to sequential indices of ARRAY, starting at zero.  If -e is supplied and
    the shell is interactive, readline is used to obtain the line.  If -n is
    supplied with a non-zero NCHARS argument, read returns after NCHARS
    characters have been read.  The -s option causes input coming from a
    terminal to not be echoed.
    
    The -t option causes read to time out and return failure if a complete line
    of input is not read within TIMEOUT seconds.  If the TMOUT variable is set,
    its value is the default timeout.  The return code is zero, unless end-of-file
    is encountered, read times out, or an invalid file descriptor is supplied as
    the argument to -u.
readonly: readonly [-af] [name[=value] ...] or readonly -p
    The given NAMEs are marked readonly and the values of these NAMEs may
    not be changed by subsequent assignment.  If the -f option is given,
    then functions corresponding to the NAMEs are so marked.  If no
    arguments are given, or if `-p' is given, a list of all readonly names
    is printed.  The `-a' option means to treat each NAME as
    an array variable.  An argument of `--' disables further option
    processing.
AMIGA:amiga~> _

Last login: Thu Dec 12 13:15:49 on ttys000
AMIGA:amiga~> read a b c
1
AMIGA:amiga~> echo "${a} ${b} ${c}"
1  
AMIGA:amiga~> read a b c
1 2
AMIGA:amiga~> echo "${a} ${b} ${c}"
1 2 
AMIGA:amiga~> read a b c
1 2 3
AMIGA:amiga~> echo "${a} ${b} ${c}"
1 2 3
AMIGA:amiga~> _