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Full Discussion: Enhancing the very limited Command Line.
Operating Systems Linux Android Enhancing the very limited Command Line. Post 302931978 by wisecracker on Saturday 17th of January 2015 04:20:57 PM
Old 01-17-2015
Enhancing the very limited Command Line.
Sometime ago, somewhere on here, I said I was going to do some coding for Android.
I installed the full dev kit and a few months ago this MBP developed a failed HDD consequently destroying the dev environment.

I got an Android phone for XMAS and downloaded a terminal program.

I then found out how VERY limited the command line was/is.
I have no intention of rooting the phone at the moment as I want to see what I can create with the limited access available...
I also do not intend downloading a text editor - see the end of this upload...

Many things we take for granted are not available and there is very limited I/O;
printf, tr, sed, od, xxd, hexdump and many many other commands are not available.
This has set me on a quest to create some tools, albeit some might be slow, to aid is shell scripting.
(A basic DEMO hex dumper using echo is elsewhere on here but here are some more simpler other ones.)

1) ENVARC - Who remembers that then eh! <wink>
This is called as . ./ENVARC and adds the TMPDIR variable that does not exist in Android and extends the PATH to include another /some/path/to/Home/bin folder for executables.
Code:
#!/system/bin/sh
# ENVARC
PATH=$PATH:/storage/sdcard0/Home/bin
TMPDIR=/storage/sdcard0/Home/tmp

This can be called/sourced from the command line or inside any code you write...

2) reset - A terminal reset command that seems to reset the terminal and DOES clear the screen.
Code:
#!/system/bin/sh
# reset<CR>
echo -n -e "\x1Bc\x1B[0m\x1B[2J\x1B[H"
clear

3) d2u - A dos2unix workalike.
Code:
#!/system/bin/sh
# d2u <infile> [outfile]<CR>
. /storage/sdcard0/Home/bin/ENVARC
ifs_str="$IFS"
IFS=""
newfile=""
substring=0
outfile=$2
if [ "$1" == "" ]
then
	echo "Usage: d2u <infile> [outfile]..."
	exit 1
fi
if [ "$2" == "" ]
then
	outfile=$1
fi
read -s -d '' -r oldfile < $1
while [ $substring -lt ${#oldfile} ]
do
	if [ "${oldfile:$substring:1}" == $'\r' ]
	then
		substring=$((substring+1))
	else
		newfile=$newfile${oldfile:$substring:1} 
		substring=$((substring+1))
	fi
done
IFS="$ifs_str"
echo -n "$newfile" > $outfile
echo "File, $1, now converted to UNIX format..."
exit 0

And finally my editor running inside my new */bin folder, ( yes I do have Ctrl-C <wink>), cat > my_executable with Ctrl-C to exit...

A cleaned up version of the hex dumper is next then I am going to attempt a simple text editor as there are no editors either...

If there are better coding practices then I am completely open to them.

Bazza...
 

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LEARN ABOUT REDHAT

dos2unix

dos2unix(1)						      General Commands Manual						       dos2unix(1)

NAME

       dos2unix - DOS/MAC to UNIX text file format converter

SYNOPSYS

       dos2unix [options] [-c convmode] [-o file ...] [-n infile outfile ...]

       Options:

       [-hkqV] [--help] [--keepdate] [--quiet] [--version]

DESCRIPTION

       This manual page documents dos2unix, the program that converts plain text files in DOS/MAC format to UNIX format.

OPTIONS

       The following options are available:

       -h --help
	      Print online help.

       -k --keepdate
	      Keep the date stamp of output file same as input file.

       -q --quiet
	      Quiet mode. Suppress all warning and messages.

       -V --version
	      Prints version information.

       -c --convmode convmode
	      Sets conversion mode. Simulates dos2unix under SunOS.

       -o --oldfile file ...
	      Old file mode. Convert the file and write output to it. The program default to run in this mode. Wildcard names may be used.

       -n --newfile infile outfile ...
	      New  file  mode.	Convert the infile and write output to outfile. File names must be given in pairs and wildcard names should NOT be
	      used or you WILL lost your files.

EXAMPLES

       Get input from stdin and write output to stdout.

	      dos2unix

       Convert and replace a.txt. Convert and replace b.txt.

	      dos2unix a.txt b.txt

	      dos2unix -o a.txt b.txt

       Convert and replace a.txt in ASCII conversion mode.  Convert and replace b.txt in ISO conversion mode.  Convert	c.txt  from  Mac  to  Unix
       ascii format.

	      dos2unix a.txt -c iso b.txt

	      dos2unix -c ascii a.txt -c iso b.txt

	      dos2unix -c mac a.txt b.txt

       Convert and replace a.txt while keeping original date stamp.

	      dos2unix -k a.txt

	      dos2unix -k -o a.txt

       Convert a.txt and write to e.txt.

	      dos2unix -n a.txt e.txt

       Convert a.txt and write to e.txt, keep date stamp of e.txt same as a.txt.

	      dos2unix -k -n a.txt e.txt

       Convert and replace a.txt. Convert b.txt and write to e.txt.

	      dos2unix a.txt -n b.txt e.txt

	      dos2unix -o a.txt -n b.txt e.txt

       Convert c.txt and write to e.txt. Convert and replace a.txt.  Convert and replace b.txt. Convert d.txt and write to f.txt.

	      dos2unix -n c.txt e.txt -o a.txt b.txt -n d.txt f.txt

DIAGNOSTICS

BUGS

       The program does not work properly under MSDOS in stdio processing mode.  If you know why is that so, please tell me.

AUTHORS

       Benjamin Lin - <blin@socs.uts.edu.au>

       Bernd Johannes Wuebben (mac2unix mode) <wuebben@kde.org>

MISCELLANY

       Tested environment:

	      Linux 1.2.0 with GNU C 2.5.8

	      SunOS 4.1.3 with GNU C 2.6.3

	      MS-DOS 6.20 with Borland C++ 4.02

       Suggestions and bug reports are welcome.

SEE ALSO

       unix2dos(1) mac2unix(1)

1995.03.31							   dos2unix v3.0						       dos2unix(1)
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