bug#20442: bug+patch: du output misaligned on different terminals

[Pádraig Brady]

tag 20442 wontfix
close 20442
stop

On 27/04/15 20:11, L. A. Walsh wrote:
> 
> 
> 
> This is a fix/work-around for (RFE#19849 (bug#19849) which was 
> about addingg options to expand tabs and/or set a tabsize
> for output from 'du' so output would line up as intended.
> 
> Without that enhancement, the current output is "messed
> up" on terminals/consoles that don't use hard-coded-constant
> widths for tabs (like many or most of the Xterm & linux
> consoles).
> 
> Adding the switches is more work than I want to chew
> off right now, but the misaligned output made for difficult
> reading (besides looking bad), especially w/a monospace font
> where it is clear that the columns were meant to lineup.
> So I threw together a quick patch against the current 
> git source (changes limited to 'du.c').
> 
> If someone would look it over, try it, or such and apply it
> to the current coreutils source tree (it's in patch form
> against 'src/du.c') for some soon future release, (at least
> until such time as the above mentioned RFE can be addressed).
> 
> 123456789 123456789 123456789 123456789 123456789 123456789 123456789 
> 123456789 
> The current du output (example from my tmp dir) on a
> term w/o hard-coded-constant expansion looks like:
> 
> Ishtar:tools/coreutils/work/src> /usr/bin/du /tmp/t*
> 4 /tmp/t
> 1160  /tmp/t1
> 680 /tmp/t2
> 4 /tmp/tab2.patch
> 20  /tmp/tabs
> 4 /tmp/tmpf
> 4 /tmp/topcmds
> 24  /tmp/topcmds-hlps
> 24  /tmp/topcmds2
> 8 /tmp/topcmds2.txt
> 4 /tmp/tq1
> 32  /tmp/tt
> 32  /tmp/tt

In fairness, this is with the unusual case after running `tabs 2`

> *Without* the assumption of hard-coded or fixed tabs (using 
> a 8-spaces/tab as seems to be the implementors assumption /
> intention), the output columns, again, line-up vertically:
> 
> Ishtar:tools/coreutils/work/src> ./du /tmp/t*       
> 4       /tmp/t
> 1160    /tmp/t1
> 680     /tmp/t2
> 4       /tmp/tab2.patch
> 20      /tmp/tabs
> 4       /tmp/tmpf
> 4       /tmp/topcmds
> 24      /tmp/topcmds-hlps
> 24      /tmp/topcmds2
> 8       /tmp/topcmds2.txt
> 4       /tmp/tq1
> 32      /tmp/tt
> 
> 
> While not addressing the RFE, at least the original output format
> should look the same on all terminals

Thanks for the patch, however the same could be achieved
more generally with external tools. For example numbers are
better for human consumption when right aligned, so you
could achieve both with:

  du | numfmt --format %10f

cheers,
Pádraig.