fish-shell/doc_src/read.txt
Joseph Tannhuber 4acea72700 New -n option for read builtin
Usage: read -n nchars
Reads maximum of nchars characters. If nchars <= 0, there's no limit.
2014-09-03 22:48:37 -07:00

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\section read read - read line of input into variables
\subsection read-synopsis Synopsis
<tt>read [OPTIONS] [VARIABLES...]</tt>
\subsection read-description Description
<tt>read</tt> reads one line from standard
input and stores the result in one or more shell variables.
The following options are available:
- <tt>-c CMD</tt> or <tt>--command=CMD</tt> sets the initial string in the interactive mode command buffer to <tt>CMD</tt>.
- <tt>-g</tt> or <tt>--global</tt> makes the variables global.
- <tt>-l</tt> or <tt>--local</tt> makes the variables local.
- <tt>-m NAME</tt> or <tt>--mode-name=NAME</tt> specifies that the name NAME should be used to save/load the history file. If NAME is fish, the regular fish history will be available.
- <tt>-n NCHARS</tt> or <tt>--nchars=NCHARS</tt> causes \c read to return after reading NCHARS characters rather than waiting for a complete line of input.
- <tt>-p PROMPT_CMD</tt> or <tt>--prompt=PROMPT_CMD</tt> uses the output of the shell command \c PROMPT_CMD as the prompt for the interactive mode. The default prompt command is <tt>set_color green; echo read; set_color normal; echo "> "</tt>.
- <code>-s</code> or <code>--shell</code> enables syntax highlighting, tab completions and command termination suitable for entering shellscript code in the interactive mode.
- <code>-u</code> or <code>--unexport</code> prevents the variables from being exported to child processes (default behaviour).
- <code>-U</code> or <code>--universal</code> causes the specified shell variable to be made universal.
- <code>-x</code> or <code>--export</code> exports the variables to child processes.
- <code>-a</code> or <code>--array</code> stores the result as an array.
\c read reads a single line of input from stdin, breaks it into tokens
based on the <tt>IFS</tt> shell variable, and then assigns one
token to each variable specified in <tt>VARIABLES</tt>. If there are more
tokens than variables, the complete remainder is assigned to the last variable.
As a special case, if \c IFS is set to the empty string, each character of the
input is considered a separate token.
If \c -a or \c --array is provided, only one variable name is allowed and the
tokens are stored as an array in this variable.
See the documentation for \c set for more details on the scoping rules for
variables.
\subsection read-example Example
The following code stores the value 'hello' in the shell variable
<tt>$foo</tt>.
<tt>echo hello|read foo</tt>