freopen reopens a stream with a different file or mode.
Reuses stream to either open the file specified by filename or to change its access mode.
Reference: freopen
Questions tagged [freopen]
105 questions
0
votes
2 answers
Opening Multiple files, alternatives to fopen()
I am a newbie programmer and am interested in competitive programming.
I made a grader for COCI problems recently. In a function of this code, I take input from input files using a loop. Its file opening part looks like this -
int next(int id)
{
…
Labib666
- 3
- 1
- 3
0
votes
2 answers
C programming - freopen append a ? to the filename
I am writing a c program that simulates the linux shell.
In order to implement i/o redirection using redirection symbol i.e. the > symbol, i make use of freopen to replace stdout with file specified by the user.
If say the command is:
environ >…
ImNoob
- 145
- 10
0
votes
3 answers
NSLog redirecting to a file will also write to /var/log/system.log
I have application where i have to maintain a log file for that app . I am logging by using NSLog . But this will also write to the system log .How to get rid of this .
Approach :
NSString *appending_filename=[log_dir_path…
user12345
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- 14
0
votes
1 answer
freopen and execvp in c
I am doing a minor shell implementation in c, and I am stuck.
I want to be able to redirect stdin and stdout, but I am confused. In, my shell, when I want to start a program, I use the execvp function. Now I would like to be able to redirect stdout,…
user1090614
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0
votes
1 answer
Why doesn't my freopen function work?
#include
#include
#define MAXN 15
char forbid[MAXN][MAXN];
int dp[2][1<
Waceburg
- 1
- 2
0
votes
3 answers
Trying to create an output file with freopen, using non-constant string
I'm trying to create a file whose name is a string constant, but a string consisting of a constant string "List" an integer + + an extension. Here's my code:
#include
#include
#include
#include
#include…
franvergara66
- 10,524
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- 101
0
votes
1 answer
WriteFile to stdout fails after freopen
I have wrote the following code:
int fd = _dup(fileno(stdout));
FILE* tmp = freopen("tmp","w+",stdout);
HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
if (out == INVALID_HANDLE_VALUE){
//error
}
else if (out == NULL) {
//error
}
else {
…
YAKOVM
- 9,805
- 31
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- 217
0
votes
0 answers
File associated with the stdout stream
I have long multithreaded application,which code I can't add here. From main program I call
freopen ("uniq_name",w+,stdout)
After it different threads start to run .From some of them writing to stdout occures.
From some of them writing to stderr…
YAKOVM
- 9,805
- 31
- 116
- 217
-1
votes
1 answer
C++ - my program stops running `freopen` function from
In my main.cpp:
#include
#include "hashtable.h"
int main() {
printf("1hello");
freopen("2.txt", "w", stdout);
printf("2hello");
freopen("1.txt", "r", stdin);
printf("3hello");
int type;
char buffer[1000];int…
Kenny Ynnek
- 57
- 7
-1
votes
1 answer
C++: freopen (and I/O) just refuses to work
Today I'm having issues with my code. It appears that I can not get anything from input (whether file or stdin) as well as unable to print (whether from file or stdout). My code can have a lot of issues (well, this is code for a competitive…
Minh Đức Hoàng
- 47
- 4
-1
votes
2 answers
why is freopen() not working on Microsoft Visual Studio but working on CodeBlocks?
I started C++ not so long and searched so hard for different ways to read and write from/to files with no result until i tried it out on CodeBlocks which worked.. Images are attached below to point out possible errors in code though the same code…
lordvidex
- 3,581
- 3
- 17
- 25
-1
votes
1 answer
function freopen is not reading inputs
I'm trying to test freopen("inputs.txt","r",stdin); but it is not working.Here is my code below:
#include
using namespace std;
int main() {
freopen("inputs.txt","r",stdin);
int n;
cin >> n;
cout << n << endl;
…
Mahfuz Ahmed
- 42
- 7
-1
votes
2 answers
freopen and cout creating internal error
I'm trying to read and write some files, but i get "ERROR C1001, internal error happened in compiler" every time i try to std::cout something to my output.out file.
Why ?
(i used _CRT_SECURE_NO_WARNINGS in preprocesssor definition to be able to use…
NanBlanc
- 127
- 1
- 12
-1
votes
1 answer
Writing cout to a file and then back to terminal
I'm currently writing a program that writes cout to a file, until the user presses control D. After that I would like to cout again to the terminal. Here is a sample of my code
freopen(outputfile,"w",stdout);
for(;;)
{
if(cin.fail()) //user…
Rob V
- 17
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- 4
-1
votes
2 answers
Freopen Multiple File input - C++
I have tried this
...
for(int i=0;i>s!=NULL){doc[i]=doc[i]+s+" ";}
fclose(stdin);
...
}
with name is a char "doc1.txt", "doc2.txt", ...
but, this code only open…
malioboro
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