Prev: Delete Chinese characters from the filenames.
Next: Remove certain characters in a filename
From: Sidney Lambe on 1 Feb 2010 04:45
On comp.unix.shell, Ivan Shmakov <ivan(a)main.uusia.org> wrote:
>>>>>> "SL" == Sidney Lambe <sidneylambe(a)nospam.invalid> writes:
>
> [...]
>
> SL> Bash:
>
> SL> (( $aa + $bb = cc }}
>
> SL> if [ "$cc" -lt 10 ]
>
> SL> then cc=$(echo "$cc" | sed 's/.*/0&/')
>
> SL> fi
>
> SL> There are surely better ways to do it.
>
> E. g., instead of using Sed, one could simply do:
>
> ...
> then cc=0"$cc"
> ...
>
> Or, even more concise:
>
> cc=$(($aa + $bb))
> [ "$cc" -lt 10 ] && cc=0"$cc"
>
> But, as mentioned elsewhere in this group, it's better to use
> `printf' for the formatting tasks like this.
>

Thanks, Ivan. That's much better. Printf has always
baffled me. The man page is pathetically inadequate.
As is the entry in man bash.

There's a lot of printf examples in the advanced shellscripting
guide. I guess I better start playing with them. It would improve
the aesthetics/readability of the output of my scripts, I think.

Sid


From: Ivan Shmakov on 1 Feb 2010 05:28
>>>>> "SL" == Sidney Lambe <sidneylambe(a)nospam.invalid> writes:
>>>>> "IS" == Ivan Shmakov <ivan(a)main.uusia.org> wrote:
>>>>> "SL" == Sidney Lambe <sidneylambe(a)nospam.invalid> writes:

[...]

SL> then cc=$(echo "$cc" | sed 's/.*/0&/')

[...]

SL> There are surely better ways to do it.

IS> E. g., instead of using Sed, one could simply do:

[...]

IS> Or, even more concise:

IS> cc=$(($aa + $bb))

IS> [ "$cc" -lt 10 ] && cc=0"$cc"

IS> But, as mentioned elsewhere in this group, it's better to use
IS> `printf' for the formatting tasks like this.

SL> Thanks, Ivan. That's much better. Printf has always baffled me. The
SL> man page is pathetically inadequate. As is the entry in man bash.

The documentation for the GNU project's tools is maintained in
the Texinfo format. Please consider looking at, e. g.:

http://www.gnu.org/software/coreutils/manual/html_node/printf-invocation.html
http://www.gnu.org/software/coreutils/manual/libc/Output-Conversion-Syntax.html

The latter is also at:

http://www.gnu.org/software/libc/manual/html_node/Output-Conversion-Syntax.html

SL> There's a lot of printf examples in the advanced shellscripting
SL> guide. I guess I better start playing with them. It would improve
SL> the aesthetics/readability of the output of my scripts, I think.

--
FSF associate member #7257
From: Sidney Lambe on 1 Feb 2010 07:53
On comp.unix.shell, Bit Twister <BitTwister(a)mouse-potato.com>
wrote:

> On 1 Feb 2010 09:16:38 +0100, Sidney Lambe wrote:
>
>> Okay, I think I've got it. But what if a=333?
>
> For crying out loud, you seemed to have proclaimed yourself
> mister cli and run no gui desktop manager, just enter
>
> a=333 printf "%02d\n" "$a"
>
> at the command line prompt and see what happens.
>
>


For crying out loud: If you had read the thread before running
your mouth, you would have seen that I obviously did just
that.

Bit Twister often shows up when I post something and tries
to harass me.

He's one of these guys who can't handle it when someone
disagrees with them and refuses to be bullied.

Stupid punks like this are a fact of life on the Useenet.

Background noise.


Sid




From: Sidney Lambe on 1 Feb 2010 07:53
On comp.unix.shell, Ivan Shmakov <ivan(a)main.uusia.org> wrote:
>>>>>> "SL" == Sidney Lambe <sidneylambe(a)nospam.invalid> writes:
>>>>>> "IS" == Ivan Shmakov <ivan(a)main.uusia.org> wrote:
>>>>>> "SL" == Sidney Lambe <sidneylambe(a)nospam.invalid> writes:
>
> [...]
>
> SL> then cc=$(echo "$cc" | sed 's/.*/0&/')
>
> [...]
>
> SL> There are surely better ways to do it.
>
> IS> E. g., instead of using Sed, one could simply do:
>
> [...]
>
> IS> Or, even more concise:
>
> IS> cc=$(($aa + $bb))
>
> IS> [ "$cc" -lt 10 ] && cc=0"$cc"
>
> IS> But, as mentioned elsewhere in this group, it's better to use
> IS> `printf' for the formatting tasks like this.
>
> SL> Thanks, Ivan. That's much better. Printf has always baffled me. The
> SL> man page is pathetically inadequate. As is the entry in man bash.
>
> The documentation for the GNU project's tools is maintained in
> the Texinfo format. Please consider looking at, e. g.:
>
> http://www.gnu.org/software/coreutils/manual/html_node/printf-invocation.html
> http://www.gnu.org/software/coreutils/manual/libc/Output-Conversion-Syntax.html
>
> The latter is also at:
>
> http://www.gnu.org/software/libc/manual/html_node/Output-Conversion-Syntax.html
>
> SL> There's a lot of printf examples in the advanced shellscripting
> SL> guide. I guess I better start playing with them. It would improve
> SL> the aesthetics/readability of the output of my scripts, I think.
>
> --
> FSF associate member #7257

Thank again, Ivan. I'll acquire those docs and any others that
I should have here.

Sid
From: Seebs on 1 Feb 2010 16:59
On 2010-02-01, Ivan Shmakov <ivan(a)main.uusia.org> wrote:
> The documentation for the GNU project's tools is maintained in
> the Texinfo format.

Which violates the principle of least surprise to an astonishing extent.
The "info" browser remains pathologically hard to use if you happen not to
be primarily used to emacs, the HTML forms are annoying at best in a plain
text terminal, and they are not where experienced UNIX users look for
documentation.

On paper, it must have sounded great to invent a shiny new documentation
format which corrected all sorts of deficiencies. In practice, it means
that there's no simple command you can type to get "the complete text of
the manual for program X" in a searchable and usable form, and that if you
do the thing that everyone has told you to do every time you have asked
a UNIX question in your entire life, you inexplicably get shoddy and
half-baked documentation.

It really is a very bad decision.

That said, the printf command is pretty decently documented on many systems,
and it's nearly self-explanatory, except for the inexplicably stupid behavior
of %c.

-s
--
Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nospam(a)seebs.net
http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
 |  Next  |  Last
Pages: 1 2 3
Prev: Delete Chinese characters from the filenames.
Next: Remove certain characters in a filename