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Questions tagged [io]

In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world, possibly a human, or another information processing system.

In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world, possibly a human, or another information processing system.

(Source: Wikipedia [Input/Output])

I/O includes tasks such as:

  • Reading and writing files ()
  • Interacting with a user through a command-line terminal session ( / / )
  • Connecting programs so that one sends its output to the next (s)
  • Sending data over a network in packets or as a data stream ()

For the Io language, see

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Force "git status" to output color on the terminal (inside a script)

EDIT: I would like to make a recommendation that parsing colors is a generally ill-conceived idea. Part of why i wanted it was so I can both parse it and pass it along in my own script output. This is... okay, but it would probably be saner to use…
Steven Lu
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Linux: When to use scatter/gather IO (readv, writev) vs a large buffer with fread

In scatter and gather (i.e. readv and writev), Linux reads into multiple buffers and writes from multiple buffers. If say, I have a vector of 3 buffers, I can use readv, OR I can use a single buffer, which is of combined size of 3 buffers and do…
Jimm
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How do I copy and paste data into R from the clipboard?

I have my data open in another application (e.g. a spreadsheet, like Excel, or a text editor). If I copy that data to my operating system clipboard, how can I read it into R as a data.frame?
Moderat
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Fast textfile reading in c++

I am currently writing a program in c++ which includes reading lots of large text files. Each has ~400.000 lines with in extreme cases 4000 or more characters per line. Just for testing, I read one of the files using ifstream and the implementation…
Arne
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Wait Until File Is Completely Written

When a file is created (FileSystemWatcher_Created) in one directory I copy it to another. But When I create a big (>10MB) file it fails to copy the file, because it starts copying already, when the file is not yet finished creating... This causes…
levi
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How to read a file as a byte array in Scala

I can find tons of examples but they seem to either rely mostly on Java libraries or just read characters/lines/etc. I just want to read in some file and get a byte array with scala libraries - can someone help me with that?
fgysin
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How can I print 0x0a instead of 0xa using cout?

How can I print 0x0a, instead of 0xa using cout? #include using std::cout; using std::endl; using std::hex; int main() { cout << hex << showbase << 10 << endl; }
Ayrosa
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What is the motivation for Scala assignment evaluating to Unit rather than the value assigned?

What is the motivation for Scala assignment evaluating to Unit rather than the value assigned? A common pattern in I/O programming is to do things like this: while ((bytesRead = in.read(buffer)) != -1) { ... But this is not possible in Scala…
Graham Lea
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The best way to get a string from a Writer

I have a piece of code that returns a web page using the built-in template system. It accepts a ResponseWriter to which the resulting markup is written. I now want to get to the markup as a string and put it in a database in some cases. I factored…
froderik
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How to use Bash read with a timeout?

I can ask the user to press Enter by using read, and have him wait by calling sleep. But I can’t think of a way of doing both at the same time. I would like the user to be given the choice: Press Ctrl+C to Cancel, Enter to continue or just wait…
qdii
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Getting "java.nio.file.AccessDeniedException" when trying to write to a folder

For some reason I keep getting java.nio.file.AccessDeniedException every time I try to write to a folder on my computer using a java webapp on Tomcat. This folder has permissions set to full control for everyone on my computer (Windows). Does…
OneTwo
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Why is the CPU not needed to service I/O requests?

I am learning about operating systems but there is a small concept I cannot grasp. Say a process 1 is running on the CPU and then it issues an I/O request to read from a disk. For efficiency, the CPU begins executing process 2 as this request is…
Pat Murray
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How to output a character as an integer through cout?

#include using namespace std; int main() { char c1 = 0xab; signed char c2 = 0xcd; unsigned char c3 = 0xef; cout << hex; cout << c1 << endl; cout << c2 << endl; cout << c3 << endl; } I expected…
xmllmx
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How to use gdb with input redirection?

In the Terminal, I have: myapp < myfileinput But if I want to use gdb, gdb myapp < myfileinput It didn't run correctly. How to use gdb here?
user53670
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What's a reasonable way to read an entire text file as a single string?

I am sure this is an easy one; I just couldn't find the answer immediately from Google. I know I could do this (right?): text = "" File.open(path).each_line do |line| text += line end # Do something with text But that seems a bit excessive,…
Dan Tao
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