How to convert seconds since the epoch (1970-01-01 UTC) to a date in Linux? For example, Convert the time stamp 1349361711.169942 to Thu Oct 4 22:41:51 HKT 2012 You can use the date command on Linux to convert the time formats. For converting the time stamp 1349361711.169942 to the normal data format: $ date -d…
How to use ibus for inputting Chinese in Cinnamon on Fedora 19? By default, ibus is not started. If I manually start it by run $ ibus-daemon The ibus daemon is started and an icon appears in the tray area. However, no Chinese is inputted to the programs even it is turned on in the…
How to install the Cinnamon desktop environment on Fedora 19? On Fedora 19: # yum groupinstall ‘Cinnamon Desktop’ to install the packages needed for the Cinnamon desktop environment. Then, in the login screen, select ‘Cinnamon’ in the “Session” menu and you will start the Cinnamon desktop environment.
How to tell whether the shell is run in screen? For example, I run screen and it starts a bash environment. How to tell in the bash, whether it is run by screen or it is a normal bash environment? It can be identified by checking the TERM environment variable: In a bash in screen:…
Any GUI tools to crop PDF file margins on Linux? I use krop: http://arminstraub.com/computer/krop krop is a simple graphical tool to crop the pages of PDF files. To install krop on Fedora: # yum install krop
I have seen the question Better way to count total page views? I think, the better way is.. We can save the number of page views in the database. It is acceptable. But, it is not fulfilling my requirement, if many different users can appear to have the same IP Address (e.g, if they are…
I have a “t_form” table and a “t_attribute” table. It looks a little bit like below. Form table form_id | form_name | description ———————————– 1 | Laptop | Possible attributes are Model, Screen Size, OS, Cd Player 2 | Mobile | Possible attributes are Model, OS 3 | Tablet | Possible attributes are Model, Screen…
With Gnome 3, I try to start a vncserver with $ vncserver -geometry 1024×768 to start a vnc server with geometry 1024×768, which works well with Gnome 2 before. This also works for twm. However, after I connect to the vnc server, the resolution is not 1024×768. I change the geometry to other resolution and…
The Kindle Library Web interface only provide interface to delete items one by one. How to delete multiple items from my Kindle Library? This works on Chrome. First, browse deki.js to find the javascript for the “DeKi: Delete Kindle Items” plugin. Press “Ctrl + A” then “Ctrl + C” to copy all the javascript code….
How to install JRE for Chrome on Linux x86-64? Use JRE from Oracle on Fedora Linux x86-64 as the example: Download jre from http://java.com/en/download/manual.jsp?locale=en#lin . Select Linux x64. Install it by # yum install jre-7u40-linux-x64.rpm (the downloaded rpm). Make a softlink of the plugin:$ cd ~/.mozilla/plugins/; ln -s /usr/java/jre1.7.0_40/lib/amd64/libnpjp2.so ./ Restart Chrome and browse chrome://plugins/…
How to make a static library (.a) on Linux? How to generate a library from C programs in files lib1.c and lib2.c: $ gcc -c lib1.c lib2.c Create a library “libmy.a” using ar: $ ar -cvq libmy.a lib1.o lib2.o You can also list the files in a library with ar: $ ar -t libmy.a You…
How to set and get an environment variable in C on Linux? You can use the setenv and getenv POSIX APIs to set and get environment variables. To add or change environment variable: #include <stdlib.h> int setenv(const char *envname, const char *envval, int overwrite); To get value of an environment variable: #include <stdlib.h> char *getenv(const…
How to set an environment variable in csh? To set an environment variable in csh: setenv VARIABLE value Most commands used to display/manipulate the environment variables for bash are also available for csh: https://www.systutorials.com/qa/476/how-to-set-an-environment-variable-in-bash
How to set an environment variable in bash? The syntax in bash for setting an environment variable is as follows. export VARIABLE=value Note that there is no space among the variable, the equals sign (“=”) and the value. If the value has spaces, the value should be put in quotes. To check it: echo $VARIABLE…
How to show the list view in iOS 7’s calendar? Is it deleted? The list view is still available in iOS 7’s calendar. To find it, just click the magnifying glass on the top right and you will see the list view.
How to format outputs with cout in C++? You need IO Manipulators <iomanip>: Header providing parametric manipulators. There are also good tutorials on the Web: Output Formatting: http://arachnoid.com/cpptutor/student3.html Formatting Cout Output in C++ using iomanip: http://www.cprogramming.com/tutorial/iomanip.html
For example, try to less the error messages generated by the compiler with make | less Use this command: make 2>&1 | less or, if you want stderr only: make 2>&1 >/dev/null | less
g++ (version g++ (GCC) 4.8.1 20130603 (Red Hat 4.8.1-1)) report: $ g++ -std=c++11 solution.cpp -o sol solution.cpp: In function ‘int main()’: solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported Stat init_stat {.depth = 0, .moves = tv, .vec = init}; ^ solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers…
How to list the functions in a .a library on Linux? You can use the nm command: The nm utility shall display symbolic information appearing in the object file, executable file, or object-file library named by file. If no symbolic information is available for a valid input file, the nm utility shall report that fact,…
Tutorial: How to trace a function in OCaml. Use #trace. For example, to trace function f: # let rec f n = if n = 0 then 1 else f (n – 1) * n;; val f : int -> int = <fun> # #trace f;; f is now traced. # f 4;; f <–…