commandline session
$setterm -underline $ls $ls -l total 0 $ls -a . .. $setterm -underline off $ls $ls -l total 0 $ls -a . .. $
http://pluto.infoclub.in/wp-content/uploads/2013/06/setterm.c
dig DNS lookup utility
commandline session
$dig ; <> DiG 9.8.4-rpz2+rl005.12-P1 <> ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44167 ;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 17373 IN NS a.root-servers.net. . 17373 IN NS b.root-servers.net. . 17373 IN NS c.root-servers.net. . 17373 IN NS d.root-servers.net. . 17373 IN NS e.root-servers.net. . 17373 IN NS f.root-servers.net. . 17373 IN NS g.root-servers.net. . 17373 IN NS h.root-servers.net. . 17373 IN NS i.root-servers.net. . 17373 IN NS j.root-servers.net. . 17373 IN NS k.root-servers.net. . 17373 IN NS l.root-servers.net. . 17373 IN NS m.root-servers.net. ;; Query time: 53 msec ;; SERVER: 192.168.0.1#53(192.168.0.1) ;; WHEN: Thu Jun 20 20:40:07 2013 ;; MSG SIZE rcvd: 228 $ $dig a.root-servers.net ; <> DiG 9.8.4-rpz2+rl005.12-P1 <> a.root-servers.net ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27425 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;a.root-servers.net. IN A ;; ANSWER SECTION: a.root-servers.net. 14389 IN A 198.41.0.4 ;; Query time: 41 msec ;; SERVER: 192.168.0.1#53(192.168.0.1) ;; WHEN: Thu Jun 20 20:43:28 2013 ;; MSG SIZE rcvd: 52 $
true from coreutils
commandline session
$true $echo $? 0 $true hello $echo $? 0 $
mv command GNU bash
commandline session
$> 1 $echo hello > 1 $cat 1 hello $ls 1 $mv 1 2 $ls 2 $cat 2 hello $
http://pluto.infoclub.in/wp-content/uploads/2013/06/mv.c
code section
while ((c = getopt_long (argc, argv, "bfint:uvS:T", long_options, NULL))
!= -1)
{
switch (c)
{
case 'b':
make_backups = true;
if (optarg)
version_control_string = optarg;
break;
case 'f':
x.interactive = I_ALWAYS_YES;
break;
case 'i':
x.interactive = I_ASK_USER;
break;
case 'n':
x.interactive = I_ALWAYS_NO;
break;
case STRIP_TRAILING_SLASHES_OPTION:
remove_trailing_slashes = true;
break;
case 't':
if (target_directory)
error (EXIT_FAILURE, 0, _("multiple target directories specified"));
else
{
struct stat st;
if (stat (optarg, &st) != 0)
error (EXIT_FAILURE, errno, _("accessing %s"), quote (optarg));
if (! S_ISDIR (st.st_mode))
error (EXIT_FAILURE, 0, _("target %s is not a directory"),
quote (optarg));
}
target_directory = optarg;
break;
case 'T':
no_target_directory = true;
break;
case 'u':
x.update = true;
break;
case 'v':
x.verbose = true;
break;
case 'S':
make_backups = true;
backup_suffix_string = optarg;
break;
case_GETOPT_HELP_CHAR;
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
usage (EXIT_FAILURE);
}
}
http://stackoverflow.com/questions/10606250/macros-like-case-getopt-help-char-risky
cp command GNU bash
commandline session
$> 1 $echo hello > 2 $cat 1 $ $cat 2 hello $cp -b 2 cp: missing destination file operand after ‘2’ Try 'cp --help' for more information. $cp -b 2 2b $ls 1 2 2b $cat 2b hello $cp -x 2b 2c $ls 1 2 2b 2c $cat 2c hello $cp -x 2b /proc/ cp: cannot create regular file ‘/proc/2b’: Permission denied $sudo cp -x 2b /proc/ cp: cannot create regular file ‘/proc/2b’: Permission denied $cp -s 2c 2d $ls -l total 12 -rw-r--r-- 1 jeffrin jeffrin 0 Jun 1 22:28 1 -rw-r--r-- 1 jeffrin jeffrin 6 Jun 1 22:28 2 -rw-r--r-- 1 jeffrin jeffrin 6 Jun 1 22:28 2b -rw-r--r-- 1 jeffrin jeffrin 6 Jun 1 22:29 2c lrwxrwxrwx 1 jeffrin jeffrin 2 Jun 1 22:31 2d -> 2c $
http://pluto.infoclub.in/wp-content/uploads/2013/06/cp.c
http://stackoverflow.com/questions/5740042/enum-use-in-a-c-program
Scatter Plot using R
ABOUT SCATTER PLOT
A scatter plot (also called a scatterplot, scatter graph, scatter chart, scattergram, or scatter diagram) [3] is a type of plot or mathematical diagram using Cartesian coordinates to display values for typically two variables for a set of data. If the points are color-coded, one additional variable can be displayed. The data are displayed as a collection of points, each having the value of one variable determining the position on the horizontal axis and the value of the other variable determining the position on the vertical axis.[4]
ABOUT R
R is a programming language and free software environment for statistical computing and graphics supported by the R Foundation for Statistical Computing.[6] The R language is widely used among statisticians and data miners for developing statistical software[7] and data analysis.[8] Polls, data mining surveys, and studies of scholarly literature databases show substantial increases in popularity in recent years.[9] As of January 2019, R ranks 12th in the TIOBE index, a measure of popularity of programming languages.[10] A GNU package,[11] source code for the R software environment is written primarily in C, Fortran and R itself,[12] and is freely available under the GNU General Public License. Pre-compiled binary versions are provided for various operating systems. Although R has a command line interface, there are several graphical user interfaces, such as RStudio, an integrated development environment.[13][14]
TYPICAL SHELL SESSION RELATED
[code lang=”r”]
> plot(1,2,3)
Error in plot.xy(xy, type, …) : invalid plot type
> plot(12,45,55,67))
Error: unexpected ‘)’ in "plot(12,45,55,67))"
> plot(12,45,55,67)
Error in plot.window(…) : invalid ‘xlim’ value
> plot(12)
> png(file="basic.png")
> plot(12)
> dev.off()
null device
1
> plot(12,32)
> plot(12,55,99)
Error in plot.xy(xy, type, …) : invalid plot type
> plot(12,b,55)
Error in xy.coords(x, y, xlabel, ylabel, log) : object ‘b’ not found
>
[/code]
LINKS
http://www.mathsisfun.com/data/scatter-xy-plots.html
http://www.biomedware.com/files/documentation/spacestat/Statistics/Regression/Regression_line.htm
<!– 
–>
https://en.wikipedia.org/wiki/Scatter_plot
https://en.wikipedia.org/wiki/R_(programming_language)
objdump tinkering
commandline session
root>objdump -f nouveau.ko nouveau.ko: file format elf64-x86-64 architecture: i386:x86-64, flags 0x00000011: HAS_RELOC, HAS_SYMS start address 0x0000000000000000 root>objdump -a nouveau.ko nouveau.ko: file format elf64-x86-64 nouveau.ko root>objdump -p nouveau.ko nouveau.ko: file format elf64-x86-64 root>objdump -g nouveau.ko nouveau.ko: file format elf64-x86-64 root>
http://www.beautifulwork.org/wp-content/uploads/2013/05/objdump.c
Erlang Tinkering
ABOUT ERLANG
Erlang (/ˈɜːrlæŋ/ UR-lang) is a general-purpose, concurrent, functional programming language, as well as a garbage-collected runtime system. The term Erlang is used interchangeably with Erlang/OTP, or OTP, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang, and a set of design principles for Erlang programs.[3] The Erlang runtime system is known for its designs that are well suited for systems with the following characteristics: Distributed Fault-tolerant Soft real-time Highly available, non-stop applications Hot swapping, where code can be changed without stopping a system.[4] The Erlang programming language is known for the following properties:[5] Immutable data Pattern matching Functional programming
TYPICAL COMMANDLINE SESSION
[bash]
$erl
[/bash]
TYPICAL ERLANG SHELL RELATED
[erlang]
Eshell V5.10.1 (abort with ^G)
1> q().
ok
2> $erl
Erlang R16B (erts-5.10.1) [source] [64-bit] [async-threads:10] [kernel-poll:false]
Eshell V5.10.1 (abort with ^G)
1> q()
1>
1> .
ok
2> $erl
Erlang R16B (erts-5.10.1) [source] [64-bit] [async-threads:10] [kernel-poll:false]
Eshell V5.10.1 (abort with ^G)
1> 10
1> .
10
2> 23.
23
3> 2#000000
3> .
0
4> 2#111111.
63
5> 8#111111.
37449
6> 16#111111.
1118481
7> 16#jeffrin
* 1: illegal integer
7> 2#jeffrin
* 1: illegal integer
7> 2#jeffrin.
* 1: illegal integer
7> 2#j
* 1: illegal integer
7> 2#cafe
* 1: illegal integer
7>
[/erlang]
LINK
https://en.wikipedia.org/wiki/Erlang_(programming_language)
Testing For File Charactereristics
commandline session
$cat test.sh #!/usr/bin/env bash # cookbook filename: checkfile # DIRPLACE=/tmp INFILE=/home/jeffrin/amazing.data OUTFILE=/home/jeffrin/more.results if [ -d "$DIRPLACE" ] then cd $DIRPLACE if [ -e "$INFILE" ] then if [ -w "$OUTFILE" ] then doscience > "$OUTFILE" else echo "can not write to $OUTFILE" fi else echo "can not read from $INFILE" fi else echo "can not cd into $DIRPLACE" fi $sh test.sh can not read from /home/jeffrin/amazing.data $> /home/jeffrin/amazing.data $sh test.sh can not write to /home/jeffrin/more.results $> /home/jeffrin/more.results $sh test.sh test.sh: 14: test.sh: doscience: not found $
related source : Bash CookBook
here-document . Bash
commandline session
$cat hdoc.sh #!/bin/bash cat $1 <<EOF EOF $sh hdoc.sh bash.txt hack hacker $ $cat bash.txt hack hacker $vim hdoc.sh $ $cat hdoc.sh #!/bin/bash grep $1 <<EOF name jeffrin age 36 sex male EOF $sh hdoc.sh 3 age 36 $