Random Junk

No such signal ! (QT)

2011-08-14T23:12:00.000-07:00

if in QT the slot and signals do not seem to work and you get errors like

Object::connect: No such signal QTableWidget::cellChanged

in the stderr , most likely it can be fixed by

removing the variable names from the call to connect

e.g

SIGNAL(cellChanged(int ,int ))

instead of

SIGNAL(cellChanged(int r,int c ))

pdfcreator not working with google chrome or srware iron

2010-05-05T23:48:00.001-07:00

It seems pdfcreator does not work directly with google chrome or srware iron
the following work around should fix it

- Go to your printers (Start - Settings - Printers)
- Right-Click PDFCreator -> Properties -> Configure Port
- Check "Run as User" (it must be selected)
- OK
- Close

sideways scrolling in links (browser)

2010-01-04T00:28:00.001-08:00

the [ and ] keys let you scroll left and right.

Not using Andnav2 anymore

2009-11-02T18:30:00.000-08:00

In my previous post I was explaining how to create map tiles for andnav2. But I have since stopped andnav2. The main problem being, I was kind of lost and wanted to use it and guess what, I get a message saying my version of andnav2 has expired and I must download a new version. Indeed when I am lost that is the perfect time for me to upgrade.
I am looking for alternatives, feel free to help me find a better one.
I tried navit but as of now still unable to get it to work on my G1.

Offline maps for G1/ HTC Dream/ android phone

2009-06-17T20:00:00.000-07:00

So I got the HTC dream, which is excellent except for the fact that whenever I used the maps app, it started to download the maps using my 3G connection and without any plan ( I use prepaid card) it was surely costimg me a lot.
Solutoin : AndNav http://www.andnav.org/

Install andnav2 from the site using the instructions provided therein. Basically install "apps installer" app from google market. download the latest .apk file and install.

now for the maps: for some luckly places on earth, someone has already made the map tiles and those can be downloaded and you need to unpack them in the andnav2\tiles\mapnik folder on your sdcard ..and you will have a bunch of files in hierarchy like
0/0/0.png.andnav

for rest of us unlucky ones:
you need to use trekbuddy to create your own map tiles using the instructions available here
only one caveat :

all the instructions are fine and it should work as mentioned on the site. but in case you dont get the directory hierarchy in the atlases folder like 0/0 as it should be, even if you follow the instruction to the doit.
If so just before you click on "create the tile package", make sure you click on "clear " and then "add selection" in the tile content package box.

after that simply copy all the files to your sd card and you are good to go !

======================
added later
I have made a small one minute video of the tile creation.

Bhaat Kerela

2009-06-04T19:51:00.000-07:00

For ages I have been wondering whats the english word for "bhaat kerela"
so here finally I have the answer

http://en.wikipedia.org/wiki/Momordica_dioica

Momordica dioica, commonly known as Teasle Gourd

mounting iso files in linux

2009-01-22T03:20:00.000-08:00

mount -t iso9660 -o loop foo.iso foodir

on archlinux you may get the following error

mount: could not find any device /dev/loop#

so overcome that you need to do a

modprobe loop

append newline at end of files

2008-12-15T23:33:00.000-08:00

Frequently when you download source code off the internet and try to compile, you end up getting a bunch of "warning: no newline at end of file" . to append a newline at the end of each *.c and *.h files use the following one liner.

find ./ $ -name "*.h" -o -name "*.cpp" $ -exec perl -i.bak -lpe 'print "\n" if eof' {} \;

ps: the space between the '{}' and '\;' at the end is required and there is no space in between "\;". else the follwing error occurs

find: missing argument to `-exec'

Sunglass

2008-12-08T04:04:00.000-08:00

While this place has mostly computer related stuff, this time I just want to say if you are running a marathon and it is expected to be sunny, a sunglass helps a LOT. Not that I am a great runner or anything. But this time I was wearing one and in between at around 34 km or so, I took them off and boy the sun looked horrible and I can easily imagine it would be far more depressing without the sunglass. FWIW I shaved 1 hr and few minutes off my last years 7 hrs 15 mins time and I am sure the sunglass made some difference.

Resize an image using Imagemagick

2008-12-01T23:17:00.000-08:00

you can just use convert to resize an image. Infact you can convert and resize in one go

convert infile.jpg -resize 10% outfile.png

"identify as" in opera

2008-11-10T01:55:00.000-08:00

People who have used opera for some time know the usefullness of the "identify as" option. In the new versions it hard to find where its located , so here's how

right click on the webpage ->edit site preferences -> network

so basically it lets you set the preferences per website , which seems to be a useful feature , except for the fact that its hard to find.

Latex solution : IEEE etc requiring all fonts to be embedded

2008-11-03T17:49:00.000-08:00

Here's an ugly solution which worked for me
( this is from here just copying it here again in case the original post get lost in an internet purge )

modify file
/usr/share/gs-afpl/8.14/lib/gs_pdfwr.ps
and change lines

/.standardfonts [
/Courier /Courier-Bold /Courier-Oblique /Courier-BoldOblique
/Helvetica /Helvetica-Bold /Helvetica-Oblique /Helvetica-BoldOblique
/Times-Roman /Times-Bold /Times-Italic /Times-BoldItalic
/Symbol /ZapfDingbats
] readonly def

into

/.standardfonts [
% /Courier /Courier-Bold /Courier-Oblique /Courier-BoldOblique
% /Helvetica /Helvetica-Bold /Helvetica-Oblique /Helvetica-BoldOblique
% /Times-Roman /Times-Bold /Times-Italic /Times-BoldItalic
% /Symbol /ZapfDingbats
] readonly def

=========
the command pdffonts shows the different fonts and whether they are embedded
sample output
pdffonts apdffile.pdf
name type emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
Arial-BoldMT TrueType no no no 2295 0
Arial-ItalicMT TrueType no no no 2296 0
ArialMT TrueType no no no 2299 0
KGDDMC+Wingdings-Regular CID TrueType yes yes no 296 0
KGDEMN+SymbolMT CID TrueType yes yes yes 301 0
Arial-BoldItalicMT TrueType no no no 306 0
KGDPPM+TimesNewRomanPS-BoldMT TrueType yes yes no 307 0
KGECBC+TimesNewRomanPSMT TrueType yes yes no 310 0
KGECDD+BookmanOldStyle-Bold TrueType yes yes no 312 0
TimesNewRomanPS-BoldItalicMT TrueType no no no 314 0
TimesNewRomanPS-ItalicMT TrueType no no no 318 0
KGECAB+TimesNewRomanPSMT CID TrueType yes yes yes 320 0
KGDPOM+TimesNewRomanPS-BoldMT CID TrueType yes yes yes 327 0

no page number in latex documents

2008-05-08T20:09:00.000-07:00

The nopageno package provides a simple way to remove page numbers from both the opening pages and the normal pages of all classes of LaTeX documents. Other than adding the package to your document, no action is necessary. No package options are available.

perl - modify numbers on each line

2007-08-16T20:07:00.000-07:00

Recently had the expression

((a1 * b2 * c3) - (a1 * b3 * c2) - (a2 * b1 * c3) + (a3 * b1 * c2) + (a2 * b3 * c1) - (a3 * b2 * c1))

in which i needed to changed all a1, b2 etc to a[0], b[1] .. i.e to arrays and with subscripts starting from 0

the following did the trick
echo "the expression here" | perl -lpe 's/(\d)/$1-1/ge; s/(\d)/\[$1\]/g'

the two s/// are required cos first one with /ge the right hand side is evaluated as an expression and hence cannot put chars like '[' inside it

rectangular emacs

2006-09-28T00:30:00.000-07:00

Just now had the occasion to use the rectangular select/cut /paste

C-x r * where * is k for kill , y for yank(paste)

to select the rectangle you have to mark(C-space) one corner of the rectangle and then take the cursor to the opposite corner).

cross-compiler hell

2006-06-26T23:39:00.000-07:00

cross-compiler are a pain in the ass .

kegel.com/crosstool is helpful in such cases

anyway if you ever build powerpc-eabi cross compiler and you get the error

powerpc-eabi-gcc hello.c -static
hello.c:(.text+0x24): undefined reference to `printf'
/opt/ppcsim/lib/gcc-lib/powerpc-eabi/3.2.1/libgcc.a(eabi.o): In function `__eabi':

use the -msim switch when compiling

dont ask me the logic behind it ..but I got it from
http://sources.redhat.com/ml/crossgcc/2002-09/msg00096.html
and it worked for me.

wrapped text in tables

2006-05-29T19:41:00.000-07:00

use package tabulary for wrapped text in tables

\begin{table}
\caption{capshon}
\begin{tabulary}{\textwidth}{lL}...
\hline
\hline
A & B \\hline
A & bbbbbbbbbbbbbbbbbbb\ X & ccccccccccccccccccccc\
\hline
\end{tabulary}...
\label{label}
\end{table}

--
for some odd reason, the label has to be where it is, when i triedto move it up below the caption i ended up with more than 100 errors

install new latex package

2006-05-29T19:39:00.000-07:00

1.Download
2. move .sty file to ..textmf/tex/latex/package-name/
3. if no .sty file .run latex on the .ins file
4. type texhash

longtable

2006-05-29T00:12:00.000-07:00

For tables of size more than one page , use package longtable

rar

2006-05-28T19:46:00.000-07:00

To extract with rar with full path use the 'x' switch
else extract using 'e'

hyperref warnings : LaTeX

2006-03-14T08:25:00.000-08:00

Package hyperref Warning: Token not allowed in a PDFDocEncoded string,
(hyperref) removing `\-command' on input line 46.

\texorpdfstring{LATEX text}{PDF text}

can be used to vary the text, depending on whether it is to be processed by LATEX or whether it will appear in the PDF bookmark. The above section heading could then be changed to

\subsubsection{An Example Heading\texorpdfstring{: $a^2+b^2=c^2$}{}}

In this case, the equation will be printed in the section heading within the document, but will not appear in the bookmark.

Reset $. at EOF

2006-03-07T23:52:00.000-08:00

When using perl $. variables, you may need to reset $. for each new file.

for example to add #!/usr/bin/perl to each .pl in the current dir do

perl -i -lpe 'print "#!/usr/bin/perl\n" if $. ==1 ; close ARGV if eof' *.pl

mget/mput with ftp

2006-03-06T22:22:00.000-08:00

While uploading/downloading multiple files using mput and mget in ftp, you prolly have to type 'y' for each file transfer. If you find it annoying you can toggle it off/on by the 'prompt' command.

Adding to table of contents ( LaTeX)

2005-11-23T07:58:00.000-08:00

Starred versions of the sectioning commands are not added to the table of contents by default, but they can be added using:

\addcontentsline{file}{type}{text}

file: This should be the extension of the file where the contents are written. So this will be toc for the table of contents, lof for the list of figures and lot for the list of tables.
type: This is the type of object you are adding to the contents. e.g. chapter, section, figure.
text: This is the text that should go in the contents.

For example, the bibliography is generated using a starred version of the \chapter command, so it doesn't get added to the table of contents. To add it to the table of contents, you can do

\addcontentsline{toc}{chapter}{\bibname}

The counter tocdepth controls the section level depth in the table of contents.

The report class file sets tocdepth to 2, which means that only the parts, chapters, sections and subsections will be entered into the table of contents. You can use \setcounter to change the value of tocdepth. For example, to also include the subsubsections, paragraphs and subparagraphs, do:

\setocounter{tocdepth}{5}

perl special variables ..ARGV

2005-09-28T21:25:00.000-07:00

just had a reason to use $ARGV in a perl one liner

ARGV The special filehandle that iterates over command-line file-filenames
names in @ARGV. Usually written as the null filehandle in the
angle operator "<>". Note that currently "ARGV" only has its
magical effect within the "<>" operator; elsewhere it is just a
plain filehandle corresponding to the last file opened by "<>".
In particular, passing "\*ARGV" as a parameter to a function
that expects a filehandle may not cause your function to
automatically read the contents of all the files in @ARGV.

more perl special variables can be found in the perlvar manpage

Float spanning columns in LaTeX

2005-08-24T01:52:00.000-07:00

Use figure* and table* to produce floats which spans across both the columns in a two column article

diff/patch

2005-08-08T01:49:00.000-07:00

copied from http://kegel.com/academy/opensource.html

Making Patches

To create a patch, you run a program called diff, and save its output to a file. For instance, if the original source tree is in directory "foobar.old", and your new sources are in directory "foobar.new", the command

diff -Naur foobar.old foobar.new > blarg.patch

will create the file 'blarg.patch' containing your changes in 'unified context diff' format.

Using Patches

To use a patch -- that is, to automatically carry out the changes described in a patch file -- you run a program called patch. For instance, if you're trying to apply the patch 'blarg.patch' to a package called foobar-0.17, you might say

cd foobar-0.17; patch -p1 < ../blarg.patch

That would merge the changes from blarg.patch into your source tree. (The -p1 tells patch to ignore the first directory in filenames in the patch; that way a patch generated against the directory foobar-0.11 will still apply properly.)

indentations

2005-08-04T00:48:00.000-07:00

So, you can either get rid of GNU emacs, or change it to use saner
values.  To do the latter, you can stick the following in your .emacs file:

(defun linux-c-mode ()
 "C mode with adjusted defaults for use with the Linux kernel."
 (interactive)
 (c-mode)
 (c-set-style "K&R")
 (setq c-basic-offset 8))

use -kr and -i8 options with indent

(stands for "K&R, 8 character indents").

Spacing in Math Mode (LaTeX)

2005-08-04T00:12:00.000-07:00

n a math environment, LaTeX ignores the spaces you type and puts in the spacing that it thinks is best. LaTeX formats mathematics the way it's done in mathematics texts. If you want different spacing, LaTeX provides the following four commands for use in math mode:

1. \; - a thick space

2. \: - a medium space

3. \, - a thin space

4. \! - a negative thin space

calculating average using perl

2005-07-20T22:52:00.000-07:00

perl -lan -e 'BEGIN{$sum=0;$num = 0}' -e '$sum += $F[0]; $num++; END{$avg=$sum/$num;print "avg:$avg"}' data.dat

to find the average of the first column in a file

search in Emacs [ word under the cursor]

2005-06-20T23:13:00.000-07:00

C-s C-w , appends the rest of the word under the cursor to the search pattern.

\[ or $$ instead of displaymath

2005-06-14T23:02:00.000-07:00

You can use \[ math formula \] or $$math formula$$ instead of
\begin{displaymath}
math formula
\end{display math}

this is particularlty useful if you dont want to write small formula and don't want to break the paragraph to type it.

Redirections in Bash

2005-06-13T00:15:00.000-07:00

command > filename 2>&1
directs both standard output and standard error to the file filename

command 2>&1 > filename
directs only the standard output to file, filename because the standard error was duplicated as standard output before the standard output was redirected

setting page ranges while printing

2005-06-12T23:45:00.000-07:00

`lp` allows you to give the page ranges to print ,

-P page-list
Specifies which pages to print in the document. The list can contain a list of numbers and ranges (#-#) separated by commas (e.g. 1,3-5,16).

latex fullpage

2005-05-12T00:56:00.000-07:00

\usepackage{fullpage} for efficient use of paper realestate

rectangle select in Emacs

2005-05-02T23:13:00.000-07:00

Working with rows & columns (rectangles)

A "rectangle" is one or more columns of text in one or more rows. Commands are available to delete rectangles, fill them with spaces, or cut and paste them.

To delineate a rectangle for a command to work on, set a mark in the first row to the left of the first column (i.e., the top left of the rectangle).

Move the cursor to the last row, then to the right of the last column (i.e. the bottom right of the rectangle).

To delete the rectangle, type Esc-x delete-rectangle

To cut a rectangle, type Esc-x kill-rectangle

To paste a killed rectangle in a new location, move the cursor to wherever the rectangle is to go and type Esc-x yank-rectangle

To replace the contents of a rectangle with spaces, type Esc-x clear-rectangle

To fill the area of the rectangle with spaces and push the original rectangle right, type Esc-x open-rectangle

script command

2005-04-28T01:15:00.000-07:00

The script command is helpful to get a transcript of the commands you enter and the output displayed on the terminal.
You start by typing script filename ( in the absence of filename the default filename is typescript)

The script command ends when you exit the forked shell by typing control-d.
more info on man script ofcourse ;)

commandline arguments in perl

2005-04-13T00:17:00.000-07:00

unlike C , in perl the first command line argument is ARGV[0] and not ARGV[1]
$#ARGV is the subscript of the last element of the @ARGV array

latex row height in tabular

2005-04-11T07:47:00.000-07:00

\renewcommand\arraystretch{MyValue}% (MyValue=1.0 is for standard spacing)

Common C++ error

2005-03-17T19:32:00.000-08:00

error:ISO C++ forbids defining types within return type
error:return type specification for constructor invalid

This mainly happens when you forget to end the class declaration with a ';'

gengetopt

2004-12-09T22:45:00.000-08:00

http://www.gnu.org/software/gengetopt/gengetopt.html
If an option is given multiple times

If an option is specified as multiple, then it can be specified multiple times at command line. In this case, say the option is called foo, the generated foo_given field in the args structure contains the number of times it was specified and the generated field foo_arg is an array containing all the values that were specified for this option.

Notice that if a default value is specified for a multiple option, that value is assigned to the option only if no other value is specified on the command line (and the corresponding _given field will be set to 1), i.e., a default value IS NOT always part of the values of a multiple option.

for (i = 0; i < args_info.string_given; ++i)

   printf ("passed string: %s\n", args_info.string_arg[i]);

C++

2004-12-05T21:27:00.000-08:00

http://www.stanford.edu/class/cs106b/winterhandouts/H06%20C++%20streams.pdf

fs.open(filename.c_str());

The above line attempts to open the file with the given filename (searching in the current directory). Note that open member function takes in a char* argument and not a C++-style string, so you must use c_str to convert it. (Sigh, this is just a weird artifact of the stream libraries being completed before the string library). Opening the file may or may not succeed (depending on whether the named file exists, what permissions it has, etc.), so before you proceed, you should check the state of the stream.

if (fs.fail()) return;

The call to fail checks if the state of the stream is unhappy, in this case, it will determine if the file was properly opened. This is essential before we start trying to output to the stream (in the same way that we check if a FILE* is NULL in C).

Emacs

2004-12-02T19:31:00.000-08:00

a few emacs shortcuts

M-/ autocompletion. It's based on the tokens in the currently open buffers.

ESC-u change a word into uppercase
ESC-c capitalise a word
C-x C-u upcase region

GNU Build system

2004-11-28T21:21:00.000-08:00

The top directory should atleast have Makefile.am and configure.in

Makefile.am in the top directory should have the subdirs where Makefiles need to be created.
e.g Makefile.am for toplevel
+++++
SUBDIRS = src
+++++

and in the directory "src" you can possibly have the following Makefile.am
++++++++++++++++
bin_PROGRAMS = hello
hello_SOURCES = hello.cpp

++++++++++++++++++

Next you need to have a configure.in in your toplevel directory
following is just a template , read and understand on your own , i have no explanations
++++++++++++++++++

AC_INIT(src/hello.cpp)

AM_CONFIG_HEADER(config.h)

AM_INIT_AUTOMAKE(hello, 0.1)

   AC_PROG_CXX

AC_PROG_INSTALL

   AC_OUTPUT(Makefile src/Makefile)

++++++++++++++++
you are pretty much done with the files at this stage ,

$aclocal
$autoconf
$touch AUTHORS NEWS README ChangeLog
$autoheader
$automake --add-missing

Installing perl modules

2004-10-28T23:17:00.000-07:00

from http://www.brandonhutchinson.com/installing_perl_modules.html

perl -MCPAN -e shell (to get an interactive CPAN shell)
perl -MCPAN -e 'install Time::JulianDay' (if you know the name of the module, you can install it directly without interacting with the CPAN shell)

Within the CPAN shell:
i /expression/ will search for a Perl module containing expression, and
install module will install the module.

Example:
perl -MCPAN -e shell
i /JulianDay/
install Time::JulianDay

Note: if you are behind a firewall, you may wish to use passive FTP with Perl's Net::FTP module. Set the environment variable FTP_PASSIVE 1 (or any non-zero value) to use passive FTP when downloading Perl modules through CPAN.

To manually install a Perl module:

1. Download the Perl module from CPAN or other site.
2. Extract the tarball.
3. Run perl Makefile.PL
4. Run make
5. Run make test
6. Run make install

Note: you should use the same compiler to build Perl modules that you used to build Perl. For example, if you are building Perl modules with gcc and are using a version of Perl that was supplied with your distribution (ex. Solaris 8 includes Perl 5.005_03), you may run into errors.

fflush(stdin)

2004-10-05T21:55:00.000-07:00

from http://www.eskimo.com/~scs/C-faq/q12.26.html

How can I flush pending input so that a user's typeahead isn't read at the next prompt? Will fflush(stdin) work?

fflush is defined only for output streams. Since its definition of ``flush'' is to complete the writing of buffered characters (not to discard them), discarding unread input would not be an analogous meaning for fflush on input streams.

There is no standard way to discard unread characters from a stdio input stream, nor would such a way be sufficient unread characters can also accumulate in other, OS-level input buffers.

References: ANSI Sec. 4.9.5.2
ISO Sec. 7.9.5.2
H&S Sec. 15.2

dired to open new directories in same buffer

2004-10-05T21:50:00.000-07:00

From http://list-archive.xemacs.org/xemacs-beta/200006/msg00277.html

Pasting the entire mail

To: X@XXXXXX.XXX
Subject: reusing dired buffer
From: samuel padgett <XXXXXXX@XXX.XXX>
Date: Thu, 29 Jun 2000 01:34:58 -0400
Message-ID: <20000629013458.B2915@durham4-099.dsl.gtei.net>

Recently, there was some discussion in the comp.emacs newsgroup

regarding dired and the way `dired-find-file' handles directories.

`dired-find-file' will always create a new buffer for each directory.

If you work in many directories, these dired buffers can accumulate

and quickly become unwieldy.



The original post asked for a way to reuse the same dired buffer when

changing directories.  Someone suggested using 'i',

`dired-maybe-insert-subdir', instead of 'RET'.  This isn't ideal,

however, because it simply inserts the contents of the subdirectory

into the current dired buffer and doesn't remove the old directory's

contents.  It also forces users to use two different keys to navigate

through directories and select files, 'i' and 'RET', instead of just

being able to use 'RET'.



I would really like to have the new directory contents replace the old

in a dired buffer.  If my cursor is positioned over a file, however, I

want dired to do the normal thing: open the file in a new buffer.

This seems to me like the most intuitive behavior.  I hacked out some

lisp code that does this:





(defun dired-follow-file ()

 "In dired, visit the file or directory on this line.

If a directory is on the current line, replace the current

dired buffer with one containing the contents of the directory.

Otherwise, invoke `dired-find-file' on the file."

 (interactive)

 (let ((filename (dired-get-filename)))

   ;; if the file is a directory, replace the buffer with the

   ;;  directory's contents

   (if (file-directory-p filename)

       (find-alternate-file filename)

     ;; otherwise simply perform a normal `dired-find-file'

     (dired-find-file))))





Now, I simply need to remap the dired keys





(add-hook

'dired-mode-hook

(lambda ()

  (local-set-key "\C-m" 'dired-follow-file)

  (local-set-key "e" 'dired-follow-file)

  (local-set-key "f" 'dired-follow-file)))





and (abracadabra) dired replaces the old directory with the new one in

the same buffer when I press 'RET'.  (Note that it's always easy to

get back to the parent directory because you can just select '..' in

the new directory listing.)



I posted this lisp snippet to comp.emacs and was asked to also send it

to  and .  Here it

is.  I hope this is helpful.



Regards,

Samuel Padgett

ssh

2004-09-24T19:55:00.000-07:00

To setup OpenSSH's sshd, you must first set up the keys used:

cd /etc/ssh ssh-keygen -b 1024 -f ssh_host_key -t rsa1 -N '' ssh-keygen -b 1024 -f ssh_host_rsa_key -t rsa -N '' ssh-keygen -b 1024 -f ssh_host_dsa_key -t dsa -N ''

common perl mistakes -1

2004-09-23T22:39:00.000-07:00

$var2 = chomp($var1);

isn't going to put the chomped $var1 in $var2

perl error

2004-09-23T20:57:00.001-07:00

Reference found where even-sized list expected at ./test.pl line 39.

-- you get this error when you try to initialize a hash like below

%hash_name = {};

from http://linux.about.com/library/cmd/blcmdl1_perl5005delta.htm

Reference found where even-sized list expected
You gave a single reference where Perl was expecting a list with an
even number of elements (for assignment to a hash). This usually means
that you used the anon hash constructor when you meant to use parens.
In any case, a hash requires key/value pairs.

%hash = { one => 1, two => 2, }; # WRONG
%hash = [ qw/ an anon array / ]; # WRONG
%hash = ( one => 1, two => 2, ); # right
%hash = qw( one 1 two 2 ); # also fine

Curly brackets are used to construct anonymous hashes. Their result is
a reference to that hash. So with %f = {} you're trying to assign a
reference (one item) to a hash. However, hashes are initialized with
lists which must have an even number of elements. Hence the warning.
The proper way to initialize an empty hash is with an empty list, which
is why %f = () works.

scanf

2004-09-21T01:09:00.000-07:00

From: http://webcourse.cs.technion.ac.il/234117/Spring2004/ar/faq_Homework.html

>>I'm having a problem using scanf. After I enter the username, the following scanf reads the "enter" I clicked. What should I do?

Instead of writing scanf("%c") you can write scanf(" %c") (with a space before %c), and it should work better. The space before the "%c" will read all white spaces (newline, tab and space) and the first non-white space will be read into the "%c". Using the scanf this way will prevent the scanf from reading the "ente

2004-09-19T03:06:00.000-07:00

find /tmp -type f -name "*.gz" -exec tar -xvzf '{}' ';'
find ./ -name "*.gz" -exec tar -xvzf {} \;

#### to exclude files in directory results
find . -name results -prune -o -type f -name "*.bc"

ls -lai | grep -v imp_file | xargs rm -f