* Bruce Momjian <[EMAIL PROTECTED]> [080506 10:56]: > What logic is there that GNU ls honors COLUMNS only in non-terminal > output? And the use of COLUMNS isn't even documented in the GNU ls > manual page. And BSD ls honors COLUMNS only for terminal output when > the ioctl fails(). It is hard to see that there is some major > expectation of how COLUMNS should behave that would make our usage > "surprising". > > If the user wants to set the wrap width for all output, they have to use > \pset columns. > > Also, because we run on some platforms that don't have that ioctl(), we > are using COLUMNS as a way of providing the width only for screen > output, like iotcl() does.
I have to admit to using the COLUMNS=... <command> trick myself.
I do have COLUMNS exported in my terminal, and often to stuff like:
ls -C | less
and I expect it to wrap at $COLUMNS (my terminal width) in my pager.
And since the GNU coreutils is pretty consistent in this regard, I often
export COLUMNS=<xxx> in scripts for cron jobs, reports, etc, to get
output that formats nicely for emails, etc.
If I ever wanted the psql wrapped format, I guess *I* would hope that
psql would work that way, simply because that's the way the other tools
I use do it. But I can see that if the other tools work differently,
then there is going to have to be some people (maybe everybody) always
double-checking the psql man page to find out again how it formats.
But since I'm not a user wanting the wrapped format, don't cater to my
hypothetical wants.
But one of the interesting things is that psql has an is *interactive*
mode (something the GNU utils don't have to worry about). So *when* you
choose to figure out your columns is important, and really impacts
behaviour too.
For instance, if I was doing a query, I often to it interactively first:
SELECT [...] FROM [....] LIMIT 50;
And when I'm sure I have the right values,expressions, column aliases,
etc, I do:
\o /tmp/output
SELECT [...] FROM [...];
\o
And in this case, I would expect that /tmp/output would have identical
formatting to the LIMITed query I just ran interactively, not matter
what setting I had for format/wrapped/auto/$COLUMNS.
> We are at least correctly documenting our behavior, which is more than
> the two 'ls' versions I saw did. If users want to set something, they
> better consult the documentation to find out how to do it.
Correctly documenting it is good, just as the version of GNU ls I have
on Debian, where I see:
`-1'
`--format=single-column'
List one file per line. This is the default for `ls' when standard
output is not a terminal.
`-C'
`--format=vertical'
List files in columns, sorted vertically. This is the default for
`ls' if standard output is a terminal. It is always the default
for the `dir' program. GNU `ls' uses variable width columns to
display as many files as possible in the fewest lines.
`-w'
`--width=COLS'
Assume the screen is COLS columns wide. The default is taken from
the terminal settings if possible; otherwise the environment
variable `COLUMNS' is used if it is set; otherwise the default is
80.
`--color [=WHEN]'
Specify whether to use color for distinguishing file types. WHEN
may be omitted, or one of:
* none - Do not use color at all. This is the default.
* auto - Only use color if standard output is a terminal.
* always - Always use color.
Specifying `--color' and no WHEN is equivalent to `--color=always'.
Piping a colorized listing through a pager like `more' or `less'
usually produces unreadable results. However, using `more -f'
does seem to work.
That's pretty straight forward, pretty explicit, and matches the
description of what Greg has been saying all along.
a.
--
Aidan Van Dyk Create like a god,
[EMAIL PROTECTED] command like a king,
http://www.highrise.ca/ work like a slave.
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