gurl—a general downloader

I like to keep things basic. Because a command-line, download program is already a part of the base package installation, it is all I need. Once I learned curl I liked it quite a bit. As always I need help remembering the options so I wrote a general wrapper script and it seems to be all I need. It features redirect following, progress bar, and resume support. It looks like this:

# gurl http://.../archlinux-2014.09.03-dual.iso
###############################                                           43.4%

gurl can be found in my general scripts repository.

LG IPS224V-PN monitor overview

LCD Monitor

I decided to get a new monitor the LG IPS224V-PN and I like it quite a bit.

First impressions

My first thought :) was that the stand could be a more rigid. It is OK, but on a desk that moves a bit, a wobble is noticeable. After I got it plugged in, the second thing I noticed, was that the color was real yellow, or rather the light was. Older LEDs can emit this din and I was a bit worried at first. Fortunately I was able to adjust it satisfactorily. A few of its specifications:

Details Value
Contrast ratio 5,000,000:1
Resolution 1920×1080
Response time 14ms
Input D-Sub, DVI, HDMI
Output Headphone

Setup

Setup was easy and monitor calibration was real straightforward and quick too. I adjusted the hardware settings as thus:

Setting Default New
Brightness 100
Contrast 50 76
Color Temp Custom Cool

I use the color temperature of cool to help balance the yellow din of the LED bulb. I did try it the normal temperature that did good with pictures if not too much white was in them:

Setting Default Alt.
Brightness 100
Contrast 50 67
Color Temp Custom
Red 50 46
Green 50 46
Blue 50 59

Ultimately I choose the cool temperature.

Other impressions

The power buttons is a large half-circle with a bright, refracting light. It is very noticeable and flashes when the monitor is in power-saving mode. It is real nice but if it is in the bedroom, like mine is, I ended up having to cover it up.

The monitor has IPS and it really does help improve the viewing angle and accurate color reproduction. I got this display for reading and it is good with that. It also is good with pictures at least as far as my mostly-professional eye is able to see. The 14ms response time, I think, is a bit on the high end for video watching. Videos will show a bit of “ghosting” but is good enough for me.

bckfile—backup a file with sequential numbering

I have discovered over the years that protecting a file, its content, and developing in a controlled, deliberate method is usually something good to keep in mind. I have learned that if I feel an document, project… is important, then to backup the data and then do the edit is the methodology I need to learn.

When I decide to backup a file, first thing I do is to see if there is a _vault directory. In any location where I had to backup previously, I created this directory. After the first time I did this I realized I was going to have to number these file backups. I reasoned out that filename_[0-9][0-9] would be a format that would be sufficient, if there was an extension it would be filename_[0-9][0-9].ext.

As I could see that file backups were something that I would regularly do, I decided to create a script that would automate this task. It tests the destination directory if the file exists. For the first backup, the script prepends 00 to the file, after that its prepend the sequential number.

The usage is basic: I define the source file and optionally the destination directory. The current directory is assumed if only the source file is specified.

An example:

$ bckfile file.txt _vault
‘file.txt’ -> ‘_vault/file_01.txt’

The script does have one limitation: the filename can only contain one period and it must be for the extension. This is necessary as determination for an otherwise intention would take a lot of work 😊.

bckfile can be found in my general scripts repository.

gt—create a gedit scratchpad

geditmp—a-script-to-create-a-gedit-scratchpad

I am really lazy with my editors. I have aliases in my shell configuration for gedit and vim to open them as quickly as possible:

alias v="vim -p"
alias sv="sudo vim -p"
alias g="bgcmd gedit"
alias sg="bgcmd gksudo geany"

This is very nice for me because I use my editors quite a bit. One thing I needed though was a command that would create and open a temporary file in gedit. The main reason for this is that, there are times, I don’t know how to name or place the file properly yet. At other times, the reason is, I like to have a scratchpad that would save information that I might forget if it was just a new file and I forgot about it or a crash happened.

The bash script

Running gt will create and open a file named with the current time (MMDDhhmm) and will be saved in the trash folder. If gt is followed by a name (e.g. gt geditmp.md) the name will be appended to the time.

geditmp-example

The name is helpful if wanting to dig the file out of the trash folder at a later time.

#!/usr/bin/bash
# (g)edit (t)emp. file — create gedit scratchpad

tmp_dir=~/.local/share/Trash/files
tme_day=$(date +%m%d%H%M)

[ ! -d "$tmp_dir" ] && mkdir -pv "$tmp_dir"

# gedit existence test
hash gedit 2>&- || { echo "Requires program \"gedit\"."; exit 1; }

# Usage
if [ "$1" = -h -o "$1" = --help ]; then
  echo "${0##*/} [name1] [name2*] — create a gedit scratchpad"
  exit 2
fi

if [ "$1" ]; then
  for name in "$@"; do
    nohup gedit "$tmp_dir"/"$tme_day"-"$name" &> /dev/null &
  done
else
  nohup gedit "$tmp_dir"/"$tme_day" &> /dev/null &
fi

WTFM (Write the Fine Manual) with Pod2man text-converter

Note: This is a guide from a lightly-proficient manual writer that’s targeted for beginning users: it’s formatting method is easy and conversion method is basic. This method may also be helpful for those that use github because it has rendering support for this method. For a more traditional approach, nixCraft has an article for that.

Because it was the authors first effort to write a man page, talk was that it was good to use Pod2Man. Pod2man is an application that converts text using Plain Old Document (POD) formatting to traditional manual (man) pages. POD markup is easy to do and pod2man is conveniently pre-installed on most Linux distributions (as it is part of the Perl package).

An example

To get a good idea of what to do, here is a basic example demonstrating the formatting (of a fictitious program dr-smile):


=encoding UTF8

=head1 NAME

dr-smile - output platitudes to help to improve one's mood

=head1 SYNOPSIS

dr-smile [B<--happy>] [B<--joke>=F<type>]

=head1 DESCRIPTION

B<dr-smile> outputs jokes and happy thoughts designed to make one fell F<--better>.  It has the ability to output pleasant thoughts, jokes, good memories, optimistic fortunes...  B<dr-smile> I<isn't> a replacement for a professional doctor, please use responsibly and enjoy.  Additional options are available in the configuration file F</etc/dr-smile.conf>.

=over 4

=item B<-h>B<--happy>

A general happy thought will be output (e.g. C<dr-smile --happy>).

=item B<-j> F<type>B<--joke>=F<type>

A good-sense joke will be told.  The types are: F<knock> and F<oddball>.  Read more in B<jokes(1)>.

=back

Formatting

There is both text formatting and section formatting that is required for a man page.

Text formatting

All the POD text formatting tags needed to know are as follows:

Bold B<text>
Italic I<text>
Link L<http://address.org >
Filename F<file>
email E<gt>name@address.comE<lt>

Man pages use two types of formatting (that I’ve ever seen). That are implemented by POD’s bold formatting and PODS filename-or-italic formatting:

Formatting type Used for
POD Bold formatting
  • Program names
  • Options
  • Manuals
POD Filename formatting
POD Italic formatting
  • Files
  • Keywords
  • Emphasis
  • Arguments
  • Occasionally manuals

Section formatting

There are three section tags that are used in pod2man (that I know of). The pod2man manual refers to these as Command Paragraphs and they are: header/category sections, item sub-sections, and “over” sub-sub-sections for additional descriptions of item sections. References to all of these are in the above example.

  • Header/Category sections are the block descriptors and their contents (like NAME, and DESCRIPTION…).
  • Item sections refer to options generally and often override =over sections for their list item.
  • Over sections refer to option descriptions.

General layout structure

Man pages follow a basic (though liberal) structure can be well represented by this:

NAME
The name of the command, followed by a one-line description of what it does.
SYNOPSIS
A representative invocation of how to run the command and options it has.
DESCRIPTION
A detailed description of the functioning of the command.
OPTIONS
A list of it's options (these are sometimes put in DESCRIPTION).
EXAMPLES
Some examples of common usage.
BUGS
List known bugs.
SEE ALSO
A list of referenced or related commands.
AUTHOR
   Specifying the contact information.
COPYRIGHT
   Specifying the copyright information.

The order of categories varies a bit from man page to man page. The first four categories are almost always the same, however the remaining vary a bit. The above layout is an mnemonic aggregate of category order of the man pages that the author has seen.

Convert pod format to manual page

Pod2man usage is basic:

pod2man dr-smile.pod > dr-smile.1

However, these additional options will probably be wanted to be added, plus compression:

pod2man --section=1 --center="dr-smile manual" --name="dr-smile" --release="1.0" dr-smile.pod | gzip > dr-smile.1.gz

Result

screenshot-manpage

Resources

xuserrun – Run a command on the currently-active user’s X.org server display

xuserrun is a bash script to run a command on the active X.org server display.  This is primarily necessary if from within another environment  (different user, console, cron, boot script…).  xuserrun gathers DISPLAY and user environmental variables via systemd and passes them on to be able to dothis. xuserrun is designed for use with only a single user X.org server display. Running it is basic:

xuserrun xclock -digital

Tto put out a notification:

xuserrun notify-send "Hello, Dave."

It’s available for Arch users in the AUR and is also downloadable on github.

Audio file encode to a video file

I wanted to convert an MP3 file to a video file to be able to use it on my PS3. The PS3 has an audio player but it doesn’t remember the position. It was an audiobook so it was best for me to convert it to a video file.

#!/usr/bin/bash
# Create video file from audio file.

# Required programs.
if ! hash ffmpeg 2>&- ; then
  echo "Requires program: ffmpeg"; exit 1; fi

# Usage.
if [ $# != 2 ] ; then
    echo "${0##*/} <image> <audio> - create video file from an audio file."
    exit 1; fi

# Files existent test.
if [ ! -f "$1" ] ; then
    echo "non-existent image: "$1""
    exit 1; fi
if [ ! -f "$2" ] ; then
    echo "non-existant audio: "$2""
    exit 1; fi

vid_nme="${2%.*}".mp4
ffmpeg -f image2 -loop 1 -i "$1" -i "$2" -c:v libx264 -tune stillimage 
  -c:a copy -strict experimental -shortest "$vid_nme"

#ffmpeg -f image2 -loop 1 -i "$1" -i "$2" -c:v libx264 -tune stillimage 
#  -c:a aac -strict experimental -b:a 192k -shortest "$3".mp4