Like in the topic, I'd like to read from standard input and print to standard output whole file with no difference between them.
program < data.txt > data.out
diff data.txt data.out // <- the same
File contains Unicode letters.
I've managed write following piece of code:
char s[100000];
int main()
{
setmode(1, _O_BINARY);
char *n;
do {
n = gets(s);
s[strlen(s)-1] = '\n';
printf("%s", s);
}
while(n);
return 0;
}
but input and output is slighty different (input: 76 465KB, output: 76 498KB)
Thanks in advance.
EDIT:
Now, it's only 2KB difference.
EDIT:
It's OK.
It could happen if the input file has \n line endings. The output file will have \r\n line endings on Windows. That could explain the difference.
If you don't want to output the \rs, you can follow this answer
Related
I'm just writing a little script to create some fake discord names.
To do this, I took a couple of .csv files with adjectives and nouns, imported them into vectors, and concatenated them. Ex:
vector<string> noun;
vector<string> adj;
infile.open("english-adjectives.txt");
while(infile.good()){
getline(infile,x);
adj.push_back(x);
}
infile.close();
shuffle(begin(adj), end(adj), rng);
I did the same thing for nouns, and then tried to concatenate them with a number, but I got a really weird result.
for (unsigned int i = 0; i < adj.size(); i++){
string temp;
temp.append(adj[i]);
temp.append(noun[i]);
discord.push_back(temp);
}
for (unsigned int i = 0; i < discord.size(); i++){
cout << discord[i] << "#0001" << "\n";
}
output:
#0001icresearch
#0001downstairs
#0001edfiddle
When I remove the "#0001" part, it prints just fine.
honoredfiddle
wanderby
deliciousofficial
Any ideas on why this is happening? I checked the newline chars in all my .csv files, and it's formatted for Unix, so I have no idea why this is happening.
Answer from Jerry Jeremiah's comment
Your CSV file was made on Windows and has Windows line endings. But
yhe computer you are running this on uses UNIX style line endings so
each line in the CSV has a \r at the end that is not being removed.
There are multiple ways of removing the \r from the CSV file - or you
could even do it inside this program after reading the data.
Took it into notepad++, edited the newlines to be just LF, and that fixed it.
[#tl;dr] I have Visual Studio Ultimate 2013 and Eclipse Neon v2(C++),
and I need to redirect the output of my program using DOS format, but
I have no idea how.
Im on Windows btw.
OK.. so I have this class assignment where I have to write a program like this:
#include <iostream>
#include <string>
using namespace std;
/* Check if the Character is lower case or not */
bool checkLowerCase(char c) {
if (c >= 'a' && c <= 'z') return true;
return false;
}
/*
* If there is any lower case letter, it will replace it will a upper case.
* example:
* "Tauros" will become "TAUROS"
* "auHU" will become "AUHU"
*/
string fixer(string s)
{
char right = ('a' - 'A');
string a = s;
for (unsigned int i = 0; i < a.length(); i++)
{
if (checkLowerCase(a[i])) {
a[i] = a[i] - right;
}
}
return a;
}
int main(void)
{
while (1) //infinite loop
{
string line;
getline(cin, line);
if (!cin) { //Professor wants us to only check end of input like this
return 0;
}
line = fixer(line);
cout << line << endl;
}
}
The input was:
aaaaaa
bbbbbb
cccccc
The output was:
aaaaaa
AAAAAA
bbbbbb
BBBBBB
cccccc
CCCCCC
Thanks for reading this far. Ok, so here's my problem.
The output is all messed up, so I need to redirect the output somewhere else (at least for testing).
I know how to do that using , , holding each line in a Array of String, reallocating if needed and then print what is on the array, but, unfortunately, my lecturer demanded us only to include and
Ohh, I dont know if it will matter, but we may not use char*, only the class string.
My lecturer told us that we have to use DOS format. But I have no clue how to do that. If someone can tell me how to do either redirect the input or the output is finee...
I have in my PC both Eclipse C++ (working glitchy) and Visual Studio Ultimate 2013 (working fine).
[Edit] Im on Windows.
AGAIN: I may only include and
For more information, here's his slide on DOS format.
*For testing purposes one redirect to/from a file
*DOS formatting will have unexpected consequences
– The end-of-line is the CR-NL combination
– A line read from the file will end with CR
– The CR character is the command to erase the
previous line!
./main < infile.txt Input is from infile.txt
./main > outfile.txt Output is to outfile.txt
./main < infile.txt > outfile.txt Both input and output are redirected
OK, so... I found instructions that helped me here:
https://msdn.microsoft.com/en-us/library/ms235639.aspx
I opened my project folder in the VisualStudio, created 2 files.
input.txt
output.txt
I opened the Developer Command Prompt for VS2013 that I had in my PC.
cd ["C://my_project_path"] //go to my project folder
cl /EHsc file.cpp
/*
cl /EHsc will compile my program (I think it only compiles one file at a time.
I have yet to test it).
*/
file < input.txt > output.txt // this command will run my program
So when I run my program like this... Instead of waiting for an input from keyboard, my program will read input.txt as the standard input. And when I try to print something to the output, it will write on the output.txt instead.
[EDIT] at the end of the link I pasted, there are explanations on how to compile multiple files and what exacly does the /EHsc do exacly
I read a text file in C++ using this code:
void main()
{
clrscr();
ifstream o("file.txt",ios::in);
while(!o.eof())
{
o.get(w);
cout<<w;
}
getch();
}
but output shows empty spaces between individual letters in the file,
although there are no such spaces in the original file.
Example: If file has hello, my output shows h e l l o.
How to rectify?
Try this
while (o>>w) cout<<w;
And since you re dealing with unicode, char wont work out. Try using
wchar_t.
In the below code i would like to also ignore the character ” . But after adding that in i still get “Mr_Bishop” as my output.
I have the following code:
ifstream getfile;
getfile.open(file,ios::in);
char data[256];
char *line;
//loop till end of file
while(!getfile.eof())
{
//get data and store to variable data
getfile.getline(data,256,'\n');
line = strtok(data," ”");
while(line != NULL)
{
cout << line << endl;
line = strtok(NULL," ");
}
}//end of while loop
my file content :
hello 7 “Mr_Bishop”
hello 10 “0913823”
Basically all i want my output to be :
hello
7
Mr_Bishop
hello
10
0913823
With this code i only get :
hello
7
"Mr_Bishop"
hello
10
"0913823"
Thanks in advance! :)
I realise i have made an error in the inner loop missing out the quote. But now i receive the following output :
hello
7
Mr_Bishop
�
hello
10
0913823
�
any help? thanks! :)
It looks like you used Wordpad or something to generate the file. You should use Notepad or Notepad++ on Windows or similar thing that will create ASCII encoding on Linux. Right now you are using what looks like UTF-8 encoding.
In addition the proper escape sequence for " is \". For instance
line = strtok(data," \"");
Once you fix your file to be in ASCII encoding, you'll find you missed something in your loop.
while(!getfile.eof())
{
//get data and store to variable data
getfile.getline(data,256,'\n');
line = strtok(data," \"");
while(line != NULL)
{
std::cout << line << std::endl;
line = strtok(NULL," \""); // THIS used to be strtok(NULL," ");
}
}//end of while loop
You missed a set of quotes there.
Correcting the file and this mistake yields the proper output.
Have a very careful look at your code:
line = strtok(data," ”");
Notice how the quotes lean at different angles (well mine do, I guess hopefully your font shows the same thing). You have included only the closing double quote in your strtok() call. However, Your data file has:
hello 7 “Mr_Bishop”
which has two different kinds of quotes. Make sure you're using all the right characters, whatever "right" is for your data.
UPDATE: Your data is probably UTF-8 encoded (that's how you got those leaning double quotes in there) and you're using strtok() which is completely unaware of UTF-8 encoding. So it's probably doing the wrong thing, splitting up the multibyte UTF-8 characters, and leaving you with rubbish at the end of the line.
I have a simple C++ program that reads stdin using scanf and returns results to stdout using printf:
#include <iostream>
using namespace std;
int main()
{
int n, x;
int f=0, s=0, t=0;
scanf("%d",&n); scanf("%d",&x);
for(int index=0; index<n; index++)
{
scanf("%d",&f);
scanf("%d",&s);
scanf("%d",&t);
if(x < f)
{
printf("first\n");
}
else if(x<s)
{
printf("second\n");
}
else if(x<t)
{
printf("third\n");
}
else
{
printf("empty\n");
}
}
return 0;
}
I am compiling with g++ and running under linux. I execute the program using a text file as input, and pipe the output to another text file as follows:
program < in.txt > out.txt
The problem is that out.txt looks like this:
result1_
result2_
result3_
...
Where '_' is an extra space at the end of each line. I am viewing out.txt in gedit.
How can I produce output without the additional space?
My input file looks like this:
2 123
123 123 123
123 234 212
Edit: I was able to find a workaround for this issue: printf("\rfoo");
Thanks for your input!
Try removing the '\n' from your printf() statements, and run the code again. If the output file looks like one long word (no spaces), then you know that the only thing being inserted after the text is that '\n'.
I assume that the editor you are using to read the out.txt file just makes it look like there is an extra space after the output.
If you are still unsure, you can write a quick program to read in out.txt and determine the ASCII code of each character.
The end of line chars are:
System Hex Value Type
Mac 0D 13 CR
DOS 0D 0A 13 10 CR LF
Unix 0A 10 LF
For a end of line on each system you can:
printf("%c", 13);
printf("%c%c", 13, 10);
printf("%c", 10);
You can use this like
printf("empty");
printf("%c", 10);
Wikipedia Newline article here.
Okay, it's a little hard to figure this out, as the example program has numerous errors:
g++ -o example example.cc
example.cc: In function 'int main()':
example.cc:19: error: 'k' was not declared in this scope
example.cc:22: error: 'o' was not declared in this scope
example.cc:24: error: 'd' was not declared in this scope
make: *** [example] Error 1
But it's not going to be your input file; your scanf will be loading whatever you're typing into ints. This example, though:
/* scan -- try scanf */
#include <stdio.h>
int main(){
int n ;
(void) scanf("%d",&n);
printf("%d\n", n);
return 0;
}
produced this result:
bash $ ./scan | od -c
42
0000000 4 2 \n
0000003
on Mac OS/X. Get us a copy of the code you're actually running, and the results of od -c.
More information is needed here, as timhon asked, which environment are you working under? Linux, Windows, Mac? Also, what text editor are you using which displays these extra spaces?
My guess is that your space isn't really a space. Run
od -hc out.txt
to double check that it is really a space.
First, the code sample you've given doesn't compile as o and d are not defined...
Second, you've probably got whitespace at the end of the line you're reading in from the input file. Try opening it in vi to see. Otherwise, you can call a trim function on each line prior to output and be done with it.
Good luck!
Make sure you're looking at the output of the program you expect; this has a syntax error (no ";" after int n).
I feel like it's not even close to this, but if you run this on Windows, you'll get \r\n as line terminators, and, maybe, under *nix, under a non-Windows-aware text editor, you'll get \r as a common blank space, since \r is not printable.
Long shot, the best way to test this is using an hexadecimal editor and see the file yourself.