On Mon, May 26, 2008 at 4:33 AM, James Youngman <[EMAIL PROTECTED]> wrote:
[rearranged]
> On Mon, May 26, 2008 at 8:37 AM, Philip Ganchev <[EMAIL PROTECTED]> wrote:
>> So I think the manual ought to mention that ls outputs tab characters,
>> that those tab characters may be displayed at various tab widths by
>> the terminal (or terminal emulator), and that therefore ls needs to
>> know where the tab stops are in the terminal.
A patch file with the suggested text is attached. The option description reads:
-T --tabsize=COLS
assume tab stops at each COLS instead of 8 positions. That
is, the terminal renders tab characters so that they end at each COLS
positions.
And the Description section includes:
If output is to a terminal, by default ls outputs tabs between file
names on each line of output.
I am trying to understand the current design and its rationale. Sorry
if my ignorant questions are annoying.
Why does ls need the tab stop positions - to output newlines so that
no file name is wrapped on two lines? Isn't there a way to tell the
terminal not to break a string when wrapping?
> Tab sizes are a property of the terminal, about which one informs the
> system in order to make text output appear correct.
Can't ls obtain the tab stop positions automatically (from the
terminal?), without needing the user to supply it?
>> Why does ls produce tab characters instead of spaces?
>
> I don't know. But the documentation does explain how to turn that off.
Sorry, I meant produce spaces to *tabulate* the output. That involves
counting how many spaces need to be printed between items so that
items on different lines align in the same columns. I don't see how
to do that from the manual.
[...]
>> And, she may prefer different tab sizes for different programs.
>
> IMHO then she is doomed to a certain background level of frustration.
> Tab sizes are a property of the terminal, about which one informs the
> system in order to make text output appear correct. Trying to do
> that whole thing backwards (i.e. telling different programs different
> things about the properties of the terminal they all use) is likely
> not to work optimally.
If every program tabulated using spaces instead of tabs, then one
parameter *inside the program* would be enough to change the
appearance of the output. And the output would look correct in any
terminal. The formatting could be done by a library which every
program could use.
--- 6.13/ls.1 2008-06-19 00:49:17.000000000 -0400
+++ 6.12/ls.1 2008-06-19 00:19:36.000000000 -0400
@@ -10,8 +10,6 @@
.PP
List information about the FILEs (the current directory by default).
Sort entries alphabetically if none of \fB\-cftuvSUX\fR nor \fB\-\-sort\fR.
-If output is to a terminal, by default ls outputs tabs between file names on
-each line of output.
.PP
Mandatory arguments to long options are mandatory for short options too.
.TP
@@ -186,9 +184,7 @@
sort by modification time
.TP
\fB\-T\fR, \fB\-\-tabsize\fR=\fICOLS\fR
-assume tab stops at each COLS instead of 8 positions.
-That is, the terminal renders tab characters so that
-they end at each COLS positions.
+assume tab stops at each COLS instead of 8
.TP
\fB\-u\fR
with \fB\-lt\fR: sort by, and show, access time
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