I know that gettimeofday() is a nice API. But how to get the number of seconds with milliseconds since the epoch time?
You can get the time at nano-seconds level (although it is not guaranteed that the last digits are accurate) by:
date +%s.%N
On a x86-64 64 bit Linux system, sometimes we may want to use the 32 bit Firefox, although the support to 64 bit Firefox is getting much better. Just for needed ones, this post introduces how to install 32 bit Firefox on 64 bit Linux (Fedora as the example). Install 32-bit firefox First, install firfox.i686…
Hadoop’s namenode and datanodes expose a bunch of TCP ports used by Hadoop’s daemons to communicate to each other or listen directly to users’ requests. These ports information are needed by both the Hadoop users and cluster administrators to write programs or configure firewalls/gateways accordingly. A post written by Philip Zeyliger from Cloudera’s blog summarizes the…
Colossus is the successor to the Google File System (GFS) as mentioned in the paper on Spanner at OSDI 2012. Colossus is also used by spanner to store its tablets. The information about Colossus is slim compared with GFS which is published in the paper at SOSP 2003. There is still some information about Colossus…
What’s the maximum number of mmap()‘ed ranges that a process can makes and how to set the limits on Linux? I have a program that mmap()s and mprotect()s lots ranges. After allocating many ranges, mprotect() starts to fail with ENOMEM error number. From the man page, ENOMEM means 2 possible problems: ENOMEM Internal kernel structures…
Update on Jan. 7, 2012: The package for the gtk application style setting on KDE 4.7 is kcm-gtk. The command to install this package is: “# yum install kcm-gtk”. One annoying thing when using KDE desktop is that the theme and style of GTK applications differ from KDE’s. The gtk-qt-engine can let us select the…
In OCaml, how to print a string as a line to STDOUT? That is, the string and the newline character, nicely? And similarly, how to print the line to STDERR? In OCaml, you may print a string with the end line character to STDOUT using the function in the Pervasives module: val print_endline : string…