Input loop: Difference between revisions

 

=={{header|Ada}}==

 

procedure Read_Stream is

end if;

end loop;

 

=={{header|ALGOL 68}}==

For file consisting of just one page - a typical linux/unix file:

The boolean functions ''physical file ended(f)'', ''logical file ended(f)'', ''page ended(f)'' and ''line ended(f)'' are also available to indicate the end of a file, page and line.

=={{header|AWK}}==

This just reads lines from stdin and prints them until EOF is read.

 

 

=={{header|C}}==

 

 

}

 

 

 

 

=={{header|C++}}==

#include <string>

#include <vector>

 

// word by word

{

std::string word;

while (is >> word)

{

}

}

 

// line by line:

{

std::string line;

while (std::getline(is, line))

{

 

 

 

{

 

 

=={{header|D}}==

{{libheader|Tango}}

import tango.text.stream.LineIterator;

 

// do something with each line

}

{{libheader|Tango}}

import tango.text.stream.SimpleIterator;

 

// do something with each word

}

 

Note that foreach variables 'line' and 'word' are transient slices. If you need to retain them for later use, you should .dup them.

 

=={{header|Forth}}==

{{works with|GNU Forth}}

 

=={{header|Haskell}}==

The whole contents of a file can be read lazily. The standard functions ''lines'' and ''words'' convert that lazily into the lists of lines resp. words. Usually, one wouldn't use extra routines for that, but just use ''readFile'' and then put 'lines' or ''words'' somewhere in the next processing step.

 

 

 

=={{header|Java}}==

Some people prefer <tt>Scanner</tt> or <tt>BufferedReader</tt>, so a way with each is presented.

Or

import java.io.IOException;

import java.io.InputStreamReader;

}

 

=={{header|OCaml}}==

line :: read_lines ic

with End_of_file ->

 

The version above will work for small files, but it is not tail-recursive. <br />

Below will be more scalable:

 

try Some (input_line ic)

with End_of_file -> None

let read_lines ic =

let rec loop acc =

| Some line -> loop (line :: acc)

in

loop []

 

Or with a higher order function:

 

let rec loop () =

with End_of_file -> ()

in

 

 

=={{header|Perl}}==

while (my $line = <FH>) {

chomp $line; # removes trailing newline

# process $line

}

 

Or you can get a list of all lines when you use it in list context:

 

=={{header|PHP}}==

if ($fh) {

while (!feof($fh)) {

}

fclose($fh);

 

Or you can get an array of all the lines in the file:

 

Or you can get the entire file as a string:

 

=={{header|Python}}==

Python file objects can be iterated like lists:

 

try:

for line in my_file:

pass # process line, includes newline

finally:

 

One can open a new stream for read and have it automatically close when done, with a new "with" statement:

 

with open(filename, 'r') as f:

for line in f:

 

You can also get lines manually from a file:

This does not mix well with the iteration, however.

 

 

for line in fileinput.input():

The fileinput module can also do inplace file editing, follow line counts, and the name of the current file being read etc.

 

=={{header|Ruby}}==

 

# process line

 

 

# process line

 

=={{header|UnixPipes}}==

the pipe 'yes XXX' produces a sequence

 

 

 

=={{header|Visual Basic .NET}}==