As a simple example, I want to write a CLI script which can print = across the entire width of the terminal window.
#!/usr/bin/env php
<?php
echo str_repeat('=', ???);
or
#!/usr/bin/env python
print '=' * ???
or
#!/usr/bin/env bash
x=0
while [ $x -lt ??? ]; do echo -n '='; let x=$x+1 done; echo
This question is related to
terminal
The answer is
yes = | head -n$(($(tput lines) * $COLUMNS)) | tr -d '\n'
Inspired by @pixelbeat's answer, here's a horizontal bar brought to existence by tput, slight misuse of printf padding/filling and tr
printf "%0$(tput cols)d" 0|tr '0' '='
yes = | head -n$(($(tput lines) * $COLUMNS)) | tr -d '\n'
In bash, the $LINES and $COLUMNS environmental variables should be able to do the trick. The will be set automatically upon any change in the terminal size. (i.e. the SIGWINCH signal)
And there's stty, from coreutils
$ stty size
60 120 # <= sample output
It will print the number of rows and columns, or height and width, respectively.
Then you can use either cut or awk to extract the part you want.
That's stty size | cut -d" " -f1 for the height/lines and stty size | cut -d" " -f2 for the width/columns
There are some cases where your rows/LINES and columns do not match the actual size of the "terminal" being used. Perhaps you may not have a "tput" or "stty" available.
Here is a bash function you can use to visually check the size. This will work up to 140 columns x 80 rows. You can adjust the maximums as needed.
function term_size
{
local i=0 digits='' tens_fmt='' tens_args=()
for i in {80..8}
do
echo $i $(( i - 2 ))
done
echo "If columns below wrap, LINES is first number in highest line above,"
echo "If truncated, LINES is second number."
for i in {1..14}
do
digits="${digits}1234567890"
tens_fmt="${tens_fmt}%10d"
tens_args=("${tens_args[@]}" $i)
done
printf "$tens_fmt\n" "${tens_args[@]}"
echo "$digits"
}
On POSIX, ultimately you want to be invoking the TIOCGWINSZ (Get WINdow SiZe) ioctl() call. Most languages ought to have some sort of wrapper for that. E.g in Perl you can use Term::Size:
use Term::Size qw( chars );
my ( $columns, $rows ) = chars \*STDOUT;
To do this in Windows CLI environment, the best way I can find is to use the mode command and parse the output.
function getTerminalSizeOnWindows() {
$output = array();
$size = array('width'=>0,'height'=>0);
exec('mode',$output);
foreach($output as $line) {
$matches = array();
$w = preg_match('/^\s*columns\:?\s*(\d+)\s*$/i',$line,$matches);
if($w) {
$size['width'] = intval($matches[1]);
} else {
$h = preg_match('/^\s*lines\:?\s*(\d+)\s*$/i',$line,$matches);
if($h) {
$size['height'] = intval($matches[1]);
}
}
if($size['width'] AND $size['height']) {
break;
}
}
return $size;
}
I hope it's useful!
NOTE: The height returned is the number of lines in the buffer, it is not the number of lines that are visible within the window. Any better options out there?
In bash, the $LINES and $COLUMNS environmental variables should be able to do the trick. The will be set automatically upon any change in the terminal size. (i.e. the SIGWINCH signal)
yes = | head -n$(($(tput lines) * $COLUMNS)) | tr -d '\n'
Inspired by @pixelbeat's answer, here's a horizontal bar brought to existence by tput, slight misuse of printf padding/filling and tr
printf "%0$(tput cols)d" 0|tr '0' '='
And there's stty, from coreutils
$ stty size
60 120 # <= sample output
It will print the number of rows and columns, or height and width, respectively.
Then you can use either cut or awk to extract the part you want.
That's stty size | cut -d" " -f1 for the height/lines and stty size | cut -d" " -f2 for the width/columns
As I mentioned in lyceus answer, his code will fail on non-English locale Windows because then the output of mode may not contain the substrings "columns" or "lines":
You can find the correct substring without looking for text:
preg_match('/---+(\n[^|]+?){2}(?<cols>\d+)/', `mode`, $matches);
$cols = $matches['cols'];
Note that I'm not even bothering with lines because it's unreliable (and I actually don't care about them).
Edit: According to comments about Windows 8 (oh you...), I think this may be more reliable:
preg_match('/CON.*:(\n[^|]+?){3}(?<cols>\d+)/', `mode`, $matches);
$cols = $matches['cols'];
Do test it out though, because I didn't test it.
To do this in Windows CLI environment, the best way I can find is to use the mode command and parse the output.
function getTerminalSizeOnWindows() {
$output = array();
$size = array('width'=>0,'height'=>0);
exec('mode',$output);
foreach($output as $line) {
$matches = array();
$w = preg_match('/^\s*columns\:?\s*(\d+)\s*$/i',$line,$matches);
if($w) {
$size['width'] = intval($matches[1]);
} else {
$h = preg_match('/^\s*lines\:?\s*(\d+)\s*$/i',$line,$matches);
if($h) {
$size['height'] = intval($matches[1]);
}
}
if($size['width'] AND $size['height']) {
break;
}
}
return $size;
}
I hope it's useful!
NOTE: The height returned is the number of lines in the buffer, it is not the number of lines that are visible within the window. Any better options out there?
There are some cases where your rows/LINES and columns do not match the actual size of the "terminal" being used. Perhaps you may not have a "tput" or "stty" available.
Here is a bash function you can use to visually check the size. This will work up to 140 columns x 80 rows. You can adjust the maximums as needed.
function term_size
{
local i=0 digits='' tens_fmt='' tens_args=()
for i in {80..8}
do
echo $i $(( i - 2 ))
done
echo "If columns below wrap, LINES is first number in highest line above,"
echo "If truncated, LINES is second number."
for i in {1..14}
do
digits="${digits}1234567890"
tens_fmt="${tens_fmt}%10d"
tens_args=("${tens_args[@]}" $i)
done
printf "$tens_fmt\n" "${tens_args[@]}"
echo "$digits"
}
yes = | head -n$(($(tput lines) * $COLUMNS)) | tr -d '\n'
As I mentioned in lyceus answer, his code will fail on non-English locale Windows because then the output of mode may not contain the substrings "columns" or "lines":
You can find the correct substring without looking for text:
preg_match('/---+(\n[^|]+?){2}(?<cols>\d+)/', `mode`, $matches);
$cols = $matches['cols'];
Note that I'm not even bothering with lines because it's unreliable (and I actually don't care about them).
Edit: According to comments about Windows 8 (oh you...), I think this may be more reliable:
preg_match('/CON.*:(\n[^|]+?){3}(?<cols>\d+)/', `mode`, $matches);
$cols = $matches['cols'];
Do test it out though, because I didn't test it.
Source: Stackoverflow.com