Commit Graph

3 Commits

Author SHA1 Message Date
FRIGN
e51a2e6d2f Use ISO-date-format in manpages
The one specified by mdoc is hard to read for non-native
speakers from countries which read the date day-first (like
Germany, Greece, North-Korea, Swamp,...).
This is also consistent with how we generally specify dates
at suckless.org.
2015-10-08 17:15:08 +02:00
FRIGN
fc886aa144 Implement od(1) v-flag
If this flag is not given, od(1) automatically replaces duplicate
adjacent lines with an '*' for each reoccurence.
If this flag is set, thus, no such filtering occurs.

In this case this would mean having to somehow keep the last printed
line in some backbuffer, building the next line and then doing the
necessary comparisons. This basically means that we duplicate the
functionality provided with uniq(1).

So instead of

$ od -t a > dump

you'd rather do

$ od -t a | uniq -f 1 -c > dump

Skipping the first field is necessary, as the addresses obviously differ.

Now, I was thinking hard why this flag even exists. If POSIX mandated
to add the address before the asterisk, so we know the offset of duplicate
occurrences, this would make sense. However, this is not the case.

Using uniq(1) also gives nicer output:
~ $ echo "111111111111111111111111111111111111111111111111" | od -t a -v | uniq -f 1 -c
      3 0000000   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1
      1 0000060  nl
      1 0000061

in comparison to

$ echo "111111111111111111111111111111111111111111111111" | od -t a
0000000   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1
*
0000060  nl
0000061

Before working on od(1), I didn't even know it would filter out
duplicate adjacent lines like that. This is also a matter of
predictability.

Concluding, the v-flag is implicitly set and users urged to just
use the existing tools provided by the system.
I don't think we would break scripts either. Firstly, it's rather
unlikely to have duplicate lines exactly matching the line-length of
od(1). Secondly, even if a script did that specifically, in the worst
case there would be a counting error or something.

Given od(1) is mostly used interactively, we can safely assume this
feature is for the benefit of the users.

Ditch this legacy POSIX crap!
 Please enter the commit message for your changes. Lines starting
2015-09-30 19:44:10 +01:00
Greg Reagle
fd0d1e4567 Created od, with improvements suggested by FRIGN 2015-09-30 19:44:10 +01:00