Groups | Search | Server Info | Keyboard shortcuts | Login | Register


Groups > comp.os.linux.misc > #71911

Manuals [Was: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use]

From "Carlos E.R." <robin_listas@es.invalid>
Newsgroups comp.os.linux.misc
Subject Manuals [Was: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use]
Date 2025-08-22 12:39 +0200
Message-ID <tvtlnlx5rc.ln2@Telcontar.valinor> (permalink)
References (17 earlier) <1086snp$rgpt$19@dont-email.me> <ffgjnlxeqh.ln2@Telcontar.valinor> <10876rt$v4bp$1@dont-email.me> <359knlxqhi.ln2@Telcontar.valinor> <1089di2$1f8lv$3@dont-email.me>

Show all headers | View raw


On 2025-08-22 11:33, Nuno Silva wrote:
> On 2025-08-21, Carlos E.R. wrote:
>> On 2025-08-21 15:27, Nuno Silva wrote:
>>> On 2025-08-21, Carlos E.R. wrote:
>>>> On 2025-08-21 12:34, The Natural Philosopher wrote:
>>>>> On 21/08/2025 10:44, Carlos E.R. wrote:
>>>>>> I do not want reference documentation.
>>>>>>
>>>>>> I primarily want documentation that allows me to start using a new
>>>>>> program, fast, and to achieve my goals.
>>>>>>
>>>>>> Once I have that, I want the reference documentation.
>>>>>
>>>>> +1001
>>> [...]
>>>> To that I added "bird.avi" as output file, but WhatsApp rejected
>>>> it. So I told ChatGpt all that. It replied giving me the missing data:
>>>>
>>>> ffmpeg -i IMAG0009.avi -vf "scale=640:-2" -c:v libx264 -profile:v \
>>>>      baseline -level 3.0 -preset fast -c:a aac -b:a 128k \
>>>>      -movflags +faststart bird_whatsapp.mp4
>>>>
>>>> and that worked. Having that command line, I modified it easily for
>>>> more resolution (scale=1024:-2). I was already familiar with all the
>>>> options, I just needed to find which would produce the wanted result,
>>>> and not spend a day on it.
>>>>
>>>>
>>>> But if I want to find in the manual what "-b" stands for, I fail. Ask
>>>> chatgpt, instant reply, it is bitrate. Oh, yes, I remember now.
>>>>
>>>> :-)
>>>>
>>>>
>>>> Oh, searching the man for "movflags" or "faststart" fails. So ask the
>>>> AI. They are in the man page for the MP3 muxer, it says. Oh, right, I
>>>> forgot that.
>>>>
>>>>
>>>> So, even a reference manual is hard to use when you want to find a
>>>> particular reference, basically using "grep".
>>>
>>> (ffmpeg's online manual is spread over more than one page, isn't it?)
>>
>> Yes.
>>
>> I don't know right now if there is a command that would search all
>> manuals and find a word.
>>
>> cer@Telcontar:~> apropos movflags
>> movflags: nothing appropriate.
>> cer@Telcontar:~>
> 
> At least here, perhaps "man -w -K movflags". Turns up ffmpeg-all and ffmpeg-formats.
> 
cer@Telcontar:~> time man -w -K movflags
/usr/share/man/man1/ffserver-all.1.gz
/usr/share/man/man1/ffmpeg-all.1.gz
/usr/share/man/man1/ffmpeg-formats.1.gz

real	0m52,869s
user	0m31,563s
sys	0m29,066s
cer@Telcontar:~>

Hum. New command. Long version:
  man --where --path --location --global-apropos movflags



        -w, --where, --path, --location
               Don't actually display the manual pages,
               but  do  print  the  location(s)  of the
               source nroff files that would be format-
               ted.

        -k, --apropos
               Equivalent to apropos.  Search the short
               manual  page  descriptions  for keywords
               and display any matches.  See apropos(1)
               for details.

        -K, --global-apropos
               Search  for  text  in  all manual pages.
               This is a  brute-force  search,  and  is
               likely  to  take  some time; if you can,
               you should specify a section  to  reduce
               the  number  of  pages  that  need to be
               searched.  Search terms  may  be  simple
               strings  (the  default),  or regular ex-
               pressions if the --regex option is used.

               Note that this searches the  sources  of
               the manual pages, not the rendered text,
               and so may include false  positives  due
               to things like comments in source files.
               Searching the  rendered  text  would  be
               much slower.



I don't see how I could replicate this with the apropos command :-?

        apropos - search the manual page names and descriptions

so, not the bodies.


> (But no, I wasn't aware of this, had to check "man man", so maybe
> there's some better man flag, or separate utility that I'm not aware of
> (besides plain grep on the man pages where possible, I guess).)
> 

Maybe. I seem to recall having done this before, but perhaps not.

-- 
Cheers, Carlos.

Back to comp.os.linux.misc | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use "Carlos E.R." <robin_listas@es.invalid> - 2025-08-19 12:35 +0200
  Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Mike Scott <usenet.16@scottsonline.org.uk.invalid> - 2025-08-19 12:18 +0100
    Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Marc Haber <mh+usenetspam1118@zugschl.us> - 2025-08-19 15:16 +0200
      Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-20 01:02 +0000
    Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Mike Scott <usenet.16@scottsonline.org.uk.invalid> - 2025-08-27 06:56 +0100
  Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-20 01:01 +0000
    Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use "Carlos E.R." <robin_listas@es.invalid> - 2025-08-20 12:52 +0200
      Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-20 22:36 +0000
        Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use "Carlos E.R." <robin_listas@es.invalid> - 2025-08-21 11:44 +0200
          Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use The Natural Philosopher <tnp@invalid.invalid> - 2025-08-21 11:34 +0100
            Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use "Carlos E.R." <robin_listas@es.invalid> - 2025-08-21 14:36 +0200
              Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Nuno Silva <nunojsilva@invalid.invalid> - 2025-08-21 14:27 +0100
                Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use "Carlos E.R." <robin_listas@es.invalid> - 2025-08-21 21:37 +0200
                Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Nuno Silva <nunojsilva@invalid.invalid> - 2025-08-22 10:33 +0100
                Manuals [Was: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] "Carlos E.R." <robin_listas@es.invalid> - 2025-08-22 12:39 +0200
              Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-22 01:12 +0000
          Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-22 01:06 +0000
            Documentation [Was: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] "Carlos E.R." <robin_listas@es.invalid> - 2025-08-22 12:26 +0200
              Re: Documentation [Was: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 23:13 +0000
    Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use John Ames <commodorejohn@gmail.com> - 2025-08-20 07:47 -0700
      Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-20 22:37 +0000
  Re: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use Stéphane CARPENTIER <sc@fiat-linux.fr> - 2025-08-20 19:25 +0000
    tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] "Carlos E.R." <robin_listas@es.invalid> - 2025-08-21 12:04 +0200
      Re: tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] Stéphane CARPENTIER <sc@fiat-linux.fr> - 2025-08-23 12:40 +0000
        Re: tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] "Carlos E.R." <robin_listas@es.invalid> - 2025-08-24 00:40 +0200
        Re: tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-23 23:15 +0000
          Re: tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] Stéphane CARPENTIER <sc@fiat-linux.fr> - 2025-08-24 11:22 +0000
            Re: tldr [WAS: Yes, You Need A Firewall On Linux - Here’s Why And Which To Use] Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-24 22:18 +0000

csiph-web