I am little surprised to find that Ubuntu Linux skips development man pages by default on cloud-based images. A quick search using apt-cache pointed out that I need to install the manpages-dev package on a Ubuntu Linux. It includes manual pages about using GNU/Linux for development. The manpages-posix-dev package includes manual pages about using a POSIX system for development. The man-db package is the on-line manual page i.e. actual man command to view man pages on a Ubuntu or Debian Linux.
Install development man pages on Ubuntu/Debian Linux
Type the following apt-get command to install various packages to view man pages for C standard library functions in Ubuntu or Debian system: $ sudo apt-get install manpages-dev man-db manpages-posix-dev Sample outputs:
How do I view man pages?
To view library calls (functions within program libraries), enter: $ man 3 function-name $ man 3 putc $ man 3 strlen $ man 3 printf $ man 3 scanf $ man 2 execve $ man 2 fork The number 3 or 2 indicates the section numbers of the manual as follows:
2 : System calls (functions provided by the kernel)
3 : Library calls (functions within program libraries)
New Linux user often get this error. Let us say you haved downloaded the RPM file from net and saved to /tmp, you may get error – no no such file or directory – when the file is really downloaded and ls command can show the same.
Answer is pretty simple rpm command needs the full path to RPM command. Use pwd command to get full path and type the following commands: ls *.rpm pwd /tmp Now install the rpm file: rpm -ivh myrpm.rpm or use full path: rpm -ivh /tmp/myrpm.rpm
Running query on uninstalled rpm package
However if you run query on uninstalled package you will get an error: # rpm -qi /tmp/bandwidth-0.12-1.el5.rf.x86_64.rpm Output:
package bandwidth-0.12-1.el5.rf.x86_64.rpm is not installed
To query an uninstalled package pass -p option to rpm command. # rpm -qip /tmp/bandwidth-0.12-1.el5.rf.x86_64.rpm Output:
Name : bandwidth Relocations: (not relocatable)
Version : 0.12 Vendor: Dag Apt Repository, http://dag.wieers.com/apt/
Release : 1.el5.rf Build Date: Sat 28 Jul 2007 03:27:28 PM CDT
Install Date: (not installed) Build Host: lisse.leuven.wieers.com
Group : Applications/Internet Source RPM: bandwidth-0.12-1.el5.rf.src.rpm
Size : 30905 License: GPL
Signature : DSA/SHA1, Sat 28 Jul 2007 03:31:11 PM CDT, Key ID a20e52146b8d79e6
Packager : Dag Wieers
URL : http://home.comcast.net/~fbui/bandwidth.html
Summary : Artificial benchmark for measuring memory bandwidth
bandwidth is an artificial benchmark for measuring memory bandwidth,
useful for identifying a computer's weak areas.
PHP offers simple but effective solution to log all errors to a log fiie. On all production web server you must turn off displaying error to end users via a web browser. Remember PHP gives out lots of information about path, database schema and all other sort of sensitive information. You are strongly advised to use error logging in place of error displaying on production web sites. The idea is quite simple only developer should able to see php error log. Continue reading “PHP Log All Errors to a Log File to Get Detailed Information”
This article (via lxer) talks about Microsoft latest FUD and how they never stop treating Linux users as idiots. Probably not while it treats its own users in the same fashion. Just take a look at the latest FUD to arrive from the Microsoft chiefs of staff – Kevin Turner, COO, claims that Vista is most secure Windows operating system ever.
Dear Mr. Turner, there is no such a thing called most secure operating system. You can just make attackers job hard, period. (keep in mind that you also need to secure Linux/BSD/UNIX oses).
And yes Microsoft CEO Steve Ballmer claimed that there will be a billion machines running Windows within a year. Few days back I had played with Vista, which has many GUI features from OSX and Compiz. Anyway 1 billion software sale is quite huge, IMHO:
The install base of Windows computers this coming 12 months will reach 1 billion,” Ballmer told the group. “If you stop and just think about that, parse that for a second, by the end of our fiscal year ’08, there will be more PCs running Windows in the world than there are automobiles.