NAME
read — read a line from standard input
DESCRIPTION
read
reads a single line from standard input.
The line is split into fields as when processed by the shell
(refer to shells in
SEE ALSO);
the first field is assigned to the first variable
var,
the second field to the second variable
var,
and so forth.
If there are more fields than there are specified
var
operands, the remaining fields and their intervening separators
are assigned to the last
var.
If there are more
vars
than fields, the remaining
vars
are set to empty strings.
The setting of variables specified by the
var
operands affect the current shell execution environment.
Standard input to
read
can be redirected from a text file.
Since
read
affects the current shell execution environment,
it is usually provided as a normal shell special (built-in) command.
Thus, if it is called in a subshell
or separate utility execution environment similar to the following,
it does not affect the shell variables in the caller's environment:
(read foo)
nohup read ...
find . -exec read ... ;
Options
read
recognizes the following options:
- -r
Do not treat a backslash character in any special way.
Consider each backslash to be part of the input line.
Opperands
read
recognizes the following operands:
- var
The name of an existing or nonexisting shell variable.
EXTERNAL INFLUENCES
Environment Variables
IFS
determines the internal field separators used to delimit fields.
RETURN VALUE
read
exits with one of the following values:
- 0
Successful completion.
- >0
End-of-file was detected or an error occurred.
EXAMPLES
Print a file with the first field of each line moved to the end of the line.
while read -r xx yy
do
printf "%s %s \n" "$yy" "$xx"
done < input_file
STANDARDS CONFORMANCE
read: SVID2, XPG2, XPG3, XPG4, POSIX.2 FIPS
Printable version
