G++ undefined reference to class::function
This is a linker error. Try: Basically, the linker is complaining about functions you used but didn’t provide an implementation for. To see all the steps the compiler performs for you, throw in a -v:
linux
Writing a simple shell in C using fork/execvp
The invalid option is because fgets() keeps the ‘\n’ when you press enter, try this when you are trying to call ls -l you are passing “-l\n” as the option, hence the message. You will have to change to
Telnet [Unable to connect to remote host: Connection refused]
0.Configure Guest OS via Virtualbox as follows. 1.Install telnet use this command in main OS terminal: 2.Edit /etc/inetd.conf in main OS using your favourite file editor with root permission,add this line: 3.Edit /etc/xinetd.conf in main OS,make its content look like following: 4.Use this command to start telnet server in main OS: That was all. By … Read more
Implementing a tree in C++
Here is a simple method of creating a hierarchical tree (n-ary with no special properties), using STL containers. It isn’t pre-built, but it is dead simple, and takes advantage of some STL properties. To create your own searching, you’d have to implement your own algorithms, but that should be fairly painless.
How to grep and replace
I need to recursively search for a specified string within all files and subdirectories within a directory and replace this string with another string. I know that the command to find it might look like this: But how can I replace every instance of string_to_find with another string?
PHP and mod_fcgid: ap_pass_brigade failed in handle_request_ipc function
The warning has nothing to do with any of the Fcgidxxx options and is simply caused by client’s closing their side of the connection before the server gets a chance to respond. From the actual source: Credit goes to Avian’s Blog who found out about it.
Unable to establish SSL connection upon wget on Ubuntu 14.04 LTS
you must be using old version of wget i had same issue. i was using wget 1.12.so to solve this issue there are 2 way: Update wget or use curl
How to get the process ID to kill a nohup process?
When using nohup and you put the task in the background, the background operator (&) will give you the PID at the command prompt. If your plan is to manually manage the process, you can save that PID and use it later to kill the process if needed, via kill PID or kill -9 PID (if you need to force kill). … Read more
RuntimeError: Invalid DISPLAY variable
You must declare matplotlib.use(‘agg’) before import pylab as plt. Reference
Read and write to binary files in C?
Does anyone have an example of code that can write to a binary file. And also code that can read a binary file and output to screen. Looking at examples I can write to a file ok But when I try to read from a file it is not outputting correctly.