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Questions tagged [file-io]

File I/O is input/output that involves the file system. This could include performing operations on directories and files, such as creation and deletion, reading files, and writing output to files.

For an introduction on File I/O in C, see C Programming / File I/O on Wikibooks.

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How to read an entire file to a string using C#?

What is the quickest way to read a text file into a string variable? I understand it can be done in several ways, such as read individual bytes and then convert those to string. I was looking for a method with minimal coding.
Shamim Hafiz - MSFT
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11 answers

C fopen vs open

Is there any reason (other than syntactic ones) that you'd want to use FILE *fdopen(int fd, const char *mode); or FILE *fopen(const char *path, const char *mode); instead of int open(const char *pathname, int flags, mode_t mode); when using C…
LJM
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11 answers

Read/Write String from/to a File in Android

I want to save a file to the internal storage by getting the text inputted from EditText. Then I want the same file to return the inputted text in String form and save it to another String which is to be used later. Here's the code: package…
Major Aly
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17 answers

C read file line by line

I wrote this function to read a line from a file: const char *readLine(FILE *file) { if (file == NULL) { printf("Error: file pointer is null."); exit(1); } int maximumLineLength = 128; char *lineBuffer = (char…
lron
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270
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15 answers

Merge PDF files

Is it possible, using Python, to merge separate PDF files? Assuming so, I need to extend this a little further. I am hoping to loop through folders in a directory and repeat this procedure. And I may be pushing my luck, but is it possible to…
Btibert3
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270
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9 answers

Read binary file as string in Ruby

I need an easy way to take a tar file and convert it into a string (and vice versa). Is there a way to do this in Ruby? My best attempt was this: file = File.open("path-to-file.tar.gz") contents = "" file.each {|line| contents << line } I thought…
Chris Bunch
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4 answers

How to open a file using the open with statement

I'm looking at how to do file input and output in Python. I've written the following code to read a list of names (one per line) from a file into another file while checking a name against the names in the file and appending text to the occurrences…
Disnami
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8 answers

Android; Check if file exists without creating a new one

I want to check if file exists in my package folder, but I don't want to create a new one. File file = new File(filePath); if(file.exists()) return true; Does this code check without creating a new file?
MBH
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Delete all files in directory (but not directory) - one liner solution

I want to delete all files inside ABC directory. When I tried with FileUtils.deleteDirectory(new File("C:/test/ABC/")); it also deletes folder ABC. Is there a one liner solution where I can delete files inside directory but not directory?
Fahim Parkar
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24 answers

How do I read an entire file into a std::string in C++?

How do I read a file into a std::string, i.e., read the whole file at once? Text or binary mode should be specified by the caller. The solution should be standard-compliant, portable and efficient. It should not needlessly copy the string's data,…
wilbur_m
252
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8 answers

In-place edits with sed on OS X

I'd like edit a file with sed on OS X. I'm using the following command: sed 's/oldword/newword/' file.txt The output is sent to the terminal. file.txt is not modified. The changes are saved to file2.txt with this command: sed…
SundayMonday
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27 answers

getResourceAsStream returns null

I'm loading a text file from within a package in a compiled JAR of my Java project. The relevant directory structure is as follows: /src/initialization/Lifepaths.txt My code loads a file by calling Class::getResourceAsStream to return a…
user1131435
248
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12 answers

Writing a Python list of lists to a csv file

I have a long list of lists of the following form --- a = [[1.2,'abc',3],[1.2,'werew',4],........,[1.4,'qew',2]] i.e. the values in the list are of different types -- float,int, strings.How do I write it into a csv file so that my output csv file…
user1403483
247
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6 answers

How do I create directory if it doesn't exist to create a file?

I have a piece of code here that breaks if the directory doesn't exist: System.IO.File.WriteAllText(filePath, content); In one line (or a few lines), is it possible to check if the directory leading to the new file doesn't exist and if not, to…
Diskdrive
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6 answers

Creating temporary files in Android

What's the best way to create a temporary file in Android? Can File.createTempFile be used? The documentation is very vague about it. In particular, it's not clear when temporary files created with File.createTempFile are deleted, if ever.
hpique
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