Troubleshooting Unix / Linux Servers

Troubleshooting tips about Linux, *BSD, UNIX, Apple OS X, programming and MS-Windows servers and desktop systems ( rss feed ).

HTTP protocol allows a client to specify a time condition for the document it requests. It is If-Modified-Since or If-Unmodified-Since. How do I use curl Unix/Linux command line option to test a server with If-Modified-Since condition and validate Last-Modified settings?

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I am using CentOS 5 on my laptop. If I open gnome-terminal by right clicking the desktop, I am getting an error that read as follows:

There was an error creating the child process for this terminal

How do I fix this problem and open a terminal by right clicking the Debian / Ubuntu / CentOS / Fedora / RHEL / Red hat Enterprise Linux 5.x desktop system?


I am using yum update command with RHN to upgrade packages installed on my server, but getting the following warning on screen :

yum update -y
Loaded plugins: product-id, protectbase, rhnplugin, security, subscription manager:
Updating certificate-based repositories.
Unable to read consumer identity
0 packages excluded due to repository protections
Setting up Update Process
Resolving Dependencies
--> Running transaction check

How do I get rid of this warning /error under RHEL 6 server?


The following question was asked in the Unix networking exam:

How do you speed up ping and traceroute command responses under Unix or Linux operating systems?


I‘m trying to install 3rd party python apps using pip command and getting the following error:

gcc -pthread -fno-strict-aliasing -fwrapv -Wall -Wstrict-prototypes -fPIC -std=c99 -O3 -fomit-frame-pointer -Isrc/ -I/usr/include/python2.7 -c src/MD2.c -o build/temp.linux-x86_64-2.7/src/MD2.o

src/MD2.c:31:20: fatal error: Python.h: No such file or directory

compilation terminated.

error: command 'gcc' failed with exit status 1

Where can I find Python.h file and how do I fix this problem under Debian or Ubuntu Linux sever based system?


How do I check swap (paging) usage under Linux operating systems using command bash/ksh line options?


One of my php script called setoptions.php is hosted on my new vps server. However, it is not working so I setup php error log as described here and, and I see the following warning repeated in my log file:

PHP Warning: fread(): Length parameter must be greater than 0 in /var/www/html/scripts/setoptions.php on line 311

The line no # 311 is as follows in my php script:
$fname = 'myappconfig.php';
$content = fread($fhandle,filesize($fname));

How do I fix this problem under Unix/Apache/php5 server?

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