file-handling is an abstraction of common actions such as creating, opening, closing, reading, updating, writing, comparing and deleting files
Questions tagged [file-handling]
2915 questions
3
votes
1 answer
Can you tie() a filehandle without a bareword glob?
I'm trying to use Device::SerialPort without a bareword glob, see questions at the bottom.
Here is their example:
$PortObj = tie (*FH, 'Device::SerialPort', $Configuration_File_Name)
print FH "text";
... but polluting the namespace with *FH feels…
KJ7LNW
- 1,437
- 5
- 11
3
votes
1 answer
Error in fromJSON("employee.json") : not all data was parsed (0 chars were parsed out of a total of 13 chars)
I was trying to read the JSON file from my r studio as a purpose of learning how to read JSON file, but suddenly i got an parsing error.
employee.json
{
"id" : ["1","2","3","4","5","6","7","8" ],
"name" :…
Gourav
- 47
- 1
- 8
3
votes
4 answers
How can I find and replace text in a larger file (150MB-250MB) with regular expressions in C#?
I am working with files that range between 150MB and 250MB, and I need to append a form feed (/f) character to each match found in a match collection. Currently, my regular expression for each match is this:
Regex myreg = new Regex("ABC:…
nightmare637
- 635
- 5
- 19
3
votes
1 answer
Does std::ofstream guarantee the old open file will be closed if opening new one?
#include
int main()
{
auto fout = std::ofstream("/tmp/a.txt");
fout.open("/tmp/b.txt"); // Will "/tmp/a.txt" be closed?
fout.open("/tmp/c.txt"); // Will "/tmp/b.txt" be closed?
}
Does std::ofstream guarantee the old open file…
xmllmx
- 39,765
- 26
- 162
- 323
3
votes
2 answers
expected declaration specifiers or ‘...’ before ‘FILE’
I am writing code in c.
I am declaring a FILE* fp at the main function (main.c).
We have other files at the project too.
So at a header file I am getting this error:
"expected declaration specifiers or ‘...’ before ‘FILE’ problem"
at this line:
void…
ChrisAsl
3
votes
1 answer
How to write logging messages to a file
I am trying to use the Python logging library. Instead of printing the messages in the console, I want to write them to a file. Based on the documentation , I'm a little unsure of how to do this. First I imported the logging in and then I created my…
gwydion93
- 1,681
- 3
- 28
- 59
3
votes
1 answer
Load and save a large amount of structured data to and from a file c++
I have a system that has lots of Blocks of data stored in a vector of structs
The struct looks like this:
class Block {
public:
Blockheader header;
uint32_t index;
std::string hash;
std::string prevhash;
std::vector…
Ariel Hurdle
- 68
- 1
- 13
3
votes
3 answers
Changing File's last modified without closing it
File's last modified time is changed only when the file is closed.
public class Main {
public static void main(String[] args) throws IOException {
File f = new File("xyz.txt");
FileWriter fwr = new FileWriter(f);
…
raj
- 3,769
- 4
- 25
- 43
3
votes
1 answer
How to create a directory on statup in spring boot project
I am making a directory to store all uploaded files in my spring boot app on startup.
The path of this directory is stored in application.properties file.
I am trying to read this path and create a directory on startupof project. I am not able to…
omkar
- 55
- 1
- 6
3
votes
1 answer
JSON.parse error while writing json data into json file
I am trying to get JSON data from a localhost URL row by row and insert it into a JSON file. When I try to open the file, I receive an error that says Multiple JSON root elements.
import urllib.parse
import urllib.request, json
import…
Devang Hingu
- 578
- 1
- 6
- 20
3
votes
8 answers
Speed Tradeoff: Frequently Reading from file vs storing it using dynamic memory
I am writing a C program which involves reading a image file and reading each pixel of image just once. So should i read file once using fread() and store it in some dynamic variable(heap variable) or frequeently use fread() for each pixel??
Image…
singhsumit
- 964
- 1
- 9
- 26
3
votes
3 answers
how to read file and print in reverse order using stack C++
I have to read text file each word at a time and then push that word to stack and then pop each word at a time to print in the display. I have tried the following code but after running the program, compiler just shows the blank screen with no…
muzzi
- 372
- 2
- 13
3
votes
2 answers
Error in free(): invalid size
#include
using namespace std;
class student
{
string name;
string reg;
public:
void getdata()
{
getline(cin,name);
getline(cin,reg);
}
void printdata()
{
cout<
ankit
- 324
- 1
- 4
- 11
3
votes
2 answers
Does BufferedWriter's write(String S) method actually buffer?
As per the Java SE 8 Documentation, the BufferedWriter class has the following methods of its own(w.r.t writing data):
write(char[] cbuf, int off, int len)
write(int c)
write(String s, int off, int len)
As I confirmed from checking the source code…
Nilashish C
- 375
- 2
- 11
3
votes
1 answer
Copying from one directory in HDFS to another directory in HDFS using JAVA
I am trying to copy the data from one directory in HDFS to another directory in HDFS but I am facing few issues. This is my code snippet.
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
…
Deepak
- 103
- 1
- 9