Input/Output for lines of text
The first line contains the number of lines to follow, followed by that number of lines of text on STDIN.
- Task
Write to STDOUT each line of input by passing it to a method as an intermediate step. The code should demonstrate these 3 things.
- Sample input with corresponding output
Input
3 hello hello world Pack my Box with 5 dozen liquor jugs
Output
hello hello world Pack my Box with 5 dozen liquor jugs
- Related tasks
11l
F do_stuff(words)
print(words)
V linecount = Int(input())
L 1..linecount
V line = input()
do_stuff(line)
Action!
The user must type in the monitor the following command after compilation and before running the program!
SET EndProg=*
CARD EndProg ;required for ALLOCATE.ACT
INCLUDE "D2:ALLOCATE.ACT" ;from the Action! Tool Kit. You must type 'SET EndProg=*' from the monitor after compiling, but before running this program!
PROC Main()
DEFINE PTR="CARD"
BYTE i,nLines
PTR ARRAY lines(256)
CHAR ARRAY line(256),p
AllocInit(0)
Put(125) PutE()
nLines=InputB()
IF nLines=0 THEN RETURN FI
FOR i=0 TO nLines-1
DO
InputS(line)
p=Alloc(line(0)+1)
MoveBlock(p,line,line(0)+1)
lines(i)=p
OD
PutE()
FOR i=0 TO nLines-1
DO
p=lines(i)
PrintE(p)
OD
FOR i=0 TO nLines-1
DO
p=lines(i)
Free(p,p(0)+1)
lines(i)=0
OD
nLines=0
RETURN
- Output:
Screenshot from Atari 8-bit computer
3 hello hello world Pack my Box with 5 dozen liquor jugs hello hello world Pack my Box with 5 dozen liquor jugs
Ada
--
-- The first line contains the number of lines to follow, followed by that
-- number of lines of text on STDIN.
--
-- Write to STDOUT each line of input by passing it to a method as an
-- intermediate step. The code should demonstrate these 3 things.
--
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
procedure Main is
Num_Lines : Integer;
begin
Get(Num_Lines);
Skip_Line;
for I in 1..Num_Lines loop
Put_Line(Get_Line);
end loop;
end Main;
Input:
3 hello hello world Pack my Box with 5 dozen liquor jugs
- Output:
hello hello world Pack my Box with 5 dozen liquor jugs
ALGOL 68
# outputs line plus a newline #
PROC show line = ( STRING line )VOID:
print( ( line, newline ) );
# copy the lines with an loop with an anonymous loop counter #
# as the loop limit is evaluated only once, we can read the #
# number of lines in the "TO" part #
TO ( INT n; read( ( n, newline ) ); n )
DO
show line( ( STRING line; read( ( line, newline ) ); line ) )
OD
ALGOL W
begin
% outputs line on a newline %
procedure showLine ( string(80) value line ); write( line );
string(80) line;
integer lineCount;
read( lineCount );
for lineNumber := 1 until lineCount do begin
read( line );
showLine( line )
end for_lineNumber
end.
Applesoft BASIC
100 GOSUB 230"INPUT LINE"
110 LET N = VAL (L$) - 1
120 IF N < 0 THEN END
130 DIM L$(N)
140 FOR I = 0 TO N
150 GOSUB 230"INPUT LINE"
160 LET L$(I) = L$
170 NEXT I
190 FOR I = 0 TO N
200 PRINT L$(I)
210 NEXT
220 END
230 LET L$ = ""
240 LET C$ = ""
250 FOR C = 0 TO 1 STEP 0
260 LET L$ = L$ + C$
270 GET C$
280 PRINT CHR$ (0)C$;
290 LET C = C$ = CHR$ (13)
300 NEXT C
310 LET C = FRE (0)
320 RETURN
Input
3 hello hello world Pack my Box with 5 dozen liquor jugs
- Output:
hello hello world Pack my Box with 5 dozen liquor jugs
AWK
# syntax: GAWK -f INPUT_OUTPUT_FOR_LINES_OF_TEXT.AWK
BEGIN {
getline n
while (i++ < n) {
getline
str = sprintf("%s%s\n",str,$0)
}
printf("%s",str)
exit(0)
}
Batch File
@echo off
setlocal enabledelayedexpansion
set /p lines=
for /l %%i in (1,1,%lines%) do set /p line%%i=
cls
for /l %%i in (1,1,%lines%) do echo !line%%i!
pause>nul
- Input:
3 line 1 this is line 2 line 3 is the longest
- Output:
line 1 this is line 2 line 3 is the longest
C
#include<stdlib.h>
#include<stdio.h>
#define LEN 100 /* Max string length */
int main()
{
char **list;
int num, i;
scanf("%d",&num);
list = (char**)malloc(num*sizeof(char*));
for(i=0;i<num;i++)
{
list[i] = (char*)malloc(LEN*sizeof(char));
fflush(stdin);
fgets(list[i],LEN,stdin);
}
printf("\n");
for(i=0;i<num;i++)
{
printf("%s",list[i]);
}
return 0;
}
Alternative code:
This program will read a number through STDIN... well, trough pipeline:
$ echo n | io
where "n" is the number of lines it will print.
When the total number of lines entered has been reached, it will display a message indicating that you must enter a number.
// Programa IO.C
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
int check_number(const char *s){
const char*t=s;
while(*t!='\n'){
if( !isdigit(*t) ) return 0;
++t;
}
return 1;
}
int main( int argc, char *argv[] )
{
char s[100],r[10];
int n=0;
FILE *fp;
fgets(s,100,stdin); // input trough stdin.
if( (fp = fopen("temporal.txt","r"))!=NULL){
fgets(r,10,fp);
n=atoi(r);
if(n>0){
--n;
fclose(fp);
fp=fopen("temporal.txt","w");
sprintf(r,"%d",n);
fputs(r,fp);
fclose(fp);
printf("%s\n",s);
}else{
fclose(fp);
remove("temporal.txt");
perror("I need a number of the lines here!\n");
}
}else{
if(check_number((const char*)s)){
fp=fopen("temporal.txt","w");
fputs(s,fp);
fclose(fp);
}else{
perror("I need a number of the lines here!\n");
}
}
return 0;
}
- Output:
$ echo 3 | ./io $ echo "hola" | ./io hola $ echo "hola mundo" | ./io hola mundo $ echo "lore ipsum et la concha de la lora latinus" | ./io lore ipsum et la concha de la lora latinus $ echo "lore ipsum et la concha de la lora latinus" | ./io I need a number of the lines here! : Success $
C++
#include <iostream>
#include <vector>
int main()
{
// read the number of lines
int numberOfLines;
std::cin >> numberOfLines;
std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); // skip to next line
// read the lines
std::vector<std::string> lines(numberOfLines);
for(int i = 0; i < numberOfLines; ++i)
{
std::getline(std::cin, lines[i]);
}
// print the lines
for(const auto& value : lines)
{
std::cout << value << "\n";
}
}
Input:
3 hello hello world Pack my Box with 5 dozen liquor jugs
- Output:
hello hello world Pack my Box with 5 dozen liquor jugs
D
void main() {
import std.stdio, std.conv, std.string;
enum doStuff = (in string line) => line.write;
foreach (_; 0 .. readln.strip.to!uint)
doStuff(readln.idup);
}
Delphi
program Output_for_Lines_of_Text;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
function QueryIntNumber(): Integer;
var
val: string;
begin
Result := 0;
repeat
Writeln('Digite a number(Enter to confirm):');
Readln(val);
if not TryStrToInt(val, Result) then
begin
Writeln('"', val, '" is not a valid number.');
Continue;
end;
if Result <= 0 then
begin
Writeln('"', val, '" must be greater then 0');
Continue;
end;
until Result > 0;
end;
var
n_lines, i: integer;
lines, line: string;
begin
lines := '';
n_lines := QueryIntNumber;
for i := 1 to n_lines do
begin
Readln(line);
if i > 1 then
lines := lines + #10;
lines := lines + line;
end;
Writeln(lines);
Readln;
end.
- Output:
Digite a number(Enter to confirm): 3 hello hello world Pack my Box with 5 dozen liquor jugs hello hello world Pack my Box with 5 dozen liquor jugs
Factor
USING: io kernel strings ;
IN: input-output
GENERIC: do-stuff ( obj -- )
M: string do-stuff print ;
readln drop [ do-stuff ] each-line
Free Pascal
This requires FPC – the FreePascal compiler – to be in a configuration enabling the use ob objects.
program head(input, output, stdErr);
type
obj = object
public
procedure method(const s: string); static;
end;
procedure obj.method(const s: string);
begin
writeLn(s);
end;
var
numberOfLines: integer;
line: string;
begin
readLn(numberOfLines);
for numberOfLines := numberOfLines downto 1 do
begin
readLn(line);
obj.method(line);
end;
end.
FreeBASIC
' FB 1.05.0 Win64
Sub printLines(lines() As String)
For i As Integer = LBound(lines) To UBound(lines)
Print lines(i)
Next
End Sub
Dim As UInteger n
Input "", n
Dim lines(1 To n) As String
For i As Integer = 1 To n
Line Input lines(i)
Next
Print
printLines lines()
Sleep
- Output:
3 hello hello world Pack my Box with 5 dozen liquor jugs hello hello world Pack my Box with 5 dozen liquor jugs
Go
package main
import (
"bufio"
"fmt"
"io"
"log"
"os"
)
func main() {
// Often we'd already have wrapped os.Stdin (or some other
// io.Reader, like an *os.File) in a bufio.Reader by this point
// and we'd use fmt.Fscanln() on that reader instead.
var lines int
n, err := fmt.Scanln(&lines)
if n != 1 || err != nil {
log.Fatal(err)
}
// Use a bufio.Scanner. This uses a SplitFunc which we can choose
// or provide our own that splits or otherwise pre-processes the
// input into tokens however we like.
//
// Could also just use bufio.ReadString('\n') but a Scanner
// with ScanLines matches (and removes) `\r?\n$` and is more
// general purpose.
//
// Normally the loop would be just:
// for scanner.Scan() {
// // use scanner.Text() or scanner.Bytes()
// }
// and we'd loop until the scan indicated EOF. But for this task
// we've got an explictly specified number of lines to read.
scanner := bufio.NewScanner(os.Stdin)
scanner.Split(bufio.ScanLines) // not needed, this is the default
for ; scanner.Scan() && lines > 0; lines-- {
doStuff(scanner.Text())
}
if err := scanner.Err(); err != nil {
log.Fatal(err)
}
// Check for too few lines, normally not needed
if lines > 0 {
log.Fatalln("early", io.EOF)
}
}
func doStuff(line string) {
fmt.Println(line)
}
Haskell
import Control.Monad
main = do
number <- getLine
input <- replicateM (read number) getLine
mapM_ putStrLn input
Input:
3 hello hello world Pack my Box with 5 dozen liquor jugs
- Output:
hello hello world Pack my Box with 5 dozen liquor jugs
J
[for number pairs links to this page.]
Example in bash. jconsole is on the PATH.
$ cat <<EOF | jconsole -js '2!:55@:0:@:(; (1!:2) 4:)@:(}. {.~ _ ". [: }: 0&{::)@:(<;.2)@:(1!:1) 3'
> 3
> hello
> hello world
> Pack my Box with 5 dozen liquor jugs
> EOF
hello
hello world
Pack my Box with 5 dozen liquor jugs
From the dictionary of j (DOJ) the data flow for the fork (f g h) is
5. Forks
As illustrated above, an isolated sequence of three verbs is called a fork; its monadic and dyadic cases are defined by:
g / \ f h | | y y g / \ f h / \ / \ x y x y
Reading from left to right
2!:55 is exit. 0: is a verb that returns 0 for any input. So now we know the script will terminate the j session with successful status.
What does it do before this? 1!:2 is "write to file", with left argument x as the data to write, and the right argument y specifies the file. 4: is a verb returning 4 for any input. File 4 is stdout.
;
is "raze". The fork
(; (1!:2) 4:)
writes data to stdout.
Good!
What is the data? (}. {.~ _ ". [: }: 0&{::) Because it has an odd number of verbs, this expresses a fork. And because {:: (fetch) is in the fork the right argument y is a vector of boxes. We know that the data has a number followed by some lines of text. Let's read the fork from left to right. The second verb, {. is "take" modified by the ~ "passive" adverb to swap arguments. Take uses a shape argument on left (x), and the data to take as y. Remembering the passive effect, the data to which take applies will be the beheaded vector of boxes---beheading removes the first line which is the number, and the fork to the right of {.~ computes the shape. Now looking at the fourth verb, ". (numbers) the default in case of error is _ (infinity meaning "all" when used along a shape dimension to take) and the data for numbers is the curtailed }: content of the first box (index origin 0). 0 is & (bonded also known as curried) to fetch. Curtailing removes the line feed. Since this gives a list of boxes, but we need to display literal data, raze "unboxes" one level of boxing. Good, if we have a list of boxed lines of input.
(<;.2)@:(1!:1) 3 (<;.2) is "< (box) ;. (cut) 2 . The 2 specifies the last item of the data as the fret, and to preserve the frets. (1!:1) 3 is "read stdin".
I chose to connect the parts into a single verb using @: (at).
With predefined verbs from standard profile we can write the simpler, more readable for native English speakers, and robust sentence which ensures a final linefeed fret and discards the frets with <;._2
exit@:0:@:(smoutput&>)@:(}. {.~ _ ". 0&{::)@:cutLF@:(1!:1) 3
Cheers! That's tacit j.
Java
import java.util.Scanner;
public class Main {
public static void doStuff(String word){
System.out.println(word);
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = Integer.parseInt(in.nextLine()); //doesn't use nextInt() so nextLine doesn't just read newline character
for(int i=0; i<n; i++){
String word = in.nextLine();
doStuff(word);
}
}
}
jq
The following works for both the C and the Go implementations of jq.
jq -Rr 'limit(tonumber; inputs)'
Julia
function dosomething(words)
print(words)
end
nlines = parse.(Int, readline())
for _ in 1:nlines
words = readline()
dosomething(words)
end
Kotlin
// version 1.1
fun output(lines: Array<String>) = println(lines.joinToString("\n"))
fun main(args: Array<String>) {
println("Enter the number of lines to be input followed by those lines:\n")
val n = readLine()!!.toInt()
val lines = Array(n) { readLine()!! }
println("\nThe lines you entered are:\n")
output(lines)
}
- Output:
Enter the number of lines to be input followed by those lines: 3 hello hello world Pack my Box with 5 dozen liquor jugs The lines you entered are: hello hello world Pack my Box with 5 dozen liquor jugs
Lua
function show (t)
for _, line in pairs(t) do print(line) end
end
local lineTable, numLines = {}, io.read()
for i = 1, numLines do table.insert(lineTable, io.read()) end
show(lineTable)
Nanoquery
// get how many lines the user wants
amount = int(input())
// loop through and get lines
lines = {}
for i in range(1, amount)
lines.append(input())
end
// output the lines that the user entered
println
for line in lines
println line
end
- Output:
3 this is a test the program will read three lines from the console this is the third line this is a test the program will read three lines from the console this is the third line
Nim
import strutils
proc write(line: string) =
echo line
let lineCount = stdin.readLine.parseInt()
for _ in 1..lineCount:
let line = stdin.readLine()
line.write()
Objeck
use System.IO.File;
class Rosetta {
function : Main(args : String[]) ~ Nil {
in : FileReader;
leaving {
if(in <> Nil) {
in->Close();
};
};
if(args->Size() = 1) {
in := FileReader->New(args[0]);
i := in->ReadString()->ToInt();
while(i-- <> 0) {
in->ReadString()->PrintLine();
};
};
}
}
PARI/GP
This task is not possible to implement directly in GP: for input()
to take a string the user would have to wrap it in quotes (and escape quotes and newlines). One must use PARI:
#include <stdio.h>
#include <stdlib.h>
#include <pari/pari.h>
int main(void);
int
main()
{
int i, n, s;
GEN vec;
// 1 MB stack, not using prime table
pari_init(1000000, 0);
scanf("%d", &n);
GEN vec = cgetg(n+1, t_VEC);
for (i = 1; i <= n; i++) {
if (1 != scanf("%s", &s)) abort();
gel(vec, i) = strtoGENstr(s);
}
pari_printf("%Ps", vec);
return 0;
}
Perl
$n = scalar <>;
do_stuff(scalar <>) for 1..$n;
sub do_stuff { print $_[0] }
Phix
without js -- (file i/o) sequence stack = {} procedure push(string line) stack = append(stack,line) end procedure procedure pop_all() while length(stack) do puts(1,stack[1]) stack = stack[2..$] end while end procedure string line = gets(0) sequence r = scanf(trim(line),"%d") if length(r)!=1 then puts(1,"input not a number\n") abort(0) end if puts(1,"\n") for i=1 to r[1][1] do line = gets(0) push(line) puts(1,"\n") end for puts(1,"===\n") pop_all()
- Output:
(or more accurately the final state of the console)
3 one two three === one two three
PowerShell
# script.ps1
$in = Get-Content $args[0]
$in[1..($in.Count-1)]
# ./script file.txt
Prolog
number_of_lines(Num) :-
current_input(In),
read_line_to_codes(In, Line),
number_codes(Num, Line).
input_lines_for_num(0, ListOfLines) :-
format('~nThe lines you entered were: ~n~n'),
maplist(format('~w~n'), ListOfLines).
input_lines_for_num(Num, CurrentLines) :-
Num > 0,
Num1 is Num - 1,
current_input(In),
read_line_to_codes(In, Line),
atom_codes(LineAsAtom, Line),
append(CurrentLines, [LineAsAtom], MoreLines),
input_lines_for_num(Num1, MoreLines).
lines :-
number_of_lines(Num),
input_lines_for_num(Num, []).
- Output:
2 ?- lines. |: 3 line 1 line 2 line 3 The lines you entered were: line 1 line 2 line 3 true ; false. 3 ?-
Python
try: input = raw_input
except: pass
def do_stuff(words):
print(words)
linecount = int(input())
for x in range(linecount):
line = input()
do_stuff(line)
Racket
#lang racket
(define (do-stuff str)
(displayln str))
;(define line-count (read)) ;reads all kind of things
(define line-count (string->number ;only reads numbers
(string-trim
(read-line))))
(for ([i (in-range line-count)])
(do-stuff (read-line)))
Raku
(formerly Perl 6)
Short version:
say get for ^get;
Verbose version:
sub do-stuff ($line) {
say $line;
}
my $n = +get;
for ^$n {
my $line = get;
do-stuff $line;
}
REXX
Programming note: this method was chosen because the standard input may be identical to the standard output.
/*REXX program writes a number of lines from the default input file (C.L.). */
#=linein() /*number of lines to be read from C.L. */
do j=1 for #; x.j=linein(); end /*obtain input lines from stdin (C.L.).*/
call stuff /*call the STUFF subroutine for writes.*/
exit /*stick a fork in it, we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
stuff: do k=1 for #; call lineout ,x.k; end; return
- output where showing the input and the output to the terminal:
3 ◄■■■■■■■ user input aaa ◄■■■■■■■ user input bbb ◄■■■■■■■ user input ccc ◄■■■■■■■ user input aaa bbb ccc
Ring
# Project : Input/Output for Lines of Text
see "n = "
give n
lines = list(number(n))
for i = 1 to n
see "lines[" + i + "] = " + nl
give lines[i]
next
see nl
printlines(lines)
func printlines(lines)
for i = 1 to len(lines)
see lines[i] + nl
next
Input:
3 hello hello world Pack my Box with 5 dozen liquor jugs
Output:
hello hello world Pack my Box with 5 dozen liquor jugs
Ruby
def do_stuff(line)
puts line
end
n = gets.to_i
n.times do
line = gets
do_stuff(line)
end
Scala
// Input/Output for Lines of Text
object IOLines extends App {
private val in = scala.io.StdIn
private val n = in.readInt()
private def doStuff(word: String): Unit = println(word)
for (_ <- 0 until n) {
val word = in.readLine()
doStuff(word)
}
}
Tcl
proc do_stuff {line} {
puts $line
}
foreach - [lrepeat [gets stdin] dummy] {
do_stuff [gets stdin]
}
Ursa
#
# input/output for lines of text
#
# get how many lines the user wants
decl int amount
set amount (in int console)
# loop through and get lines
decl string<> lines
decl int i
for (set i 0) (< i amount) (inc i)
append (in string console) lines
end for
# output the lines that the user entered
out endl console
for (set i 0) (< i amount) (inc i)
out lines<i> endl console
end for
Wren
This assumes that both Stdin and Stdout are connected to a terminal.
import "io" for Stdin
var output = Fn.new { |lines| System.print(lines.join("\n")) }
var n = Num.fromString(Stdin.readLine())
if (!n || !n.isInteger || n < 1) Fiber.abort("Number of lines must be a positive integer.")
var lines = List.filled(n, "")
for (i in 0...n) lines[i] = Stdin.readLine()
System.print()
output.call(lines)
- Output:
Sample input/output:
3 hello hello world Pack my Box with 5 dozen liquor jugs hello hello world Pack my Box with 5 dozen liquor jugs
XPL0
The input file must be redirected on the command line, for example: iotext <iotext.txt
string 0;
proc PrintLn(Str); \"method" to print a line of text
char Str;
[Text(0, Str);
CrLf(0);
];
char Line(1000);
int N, I, C;
for N:= 1 to IntIn(1) do
[I:= 0;
loop [repeat C:= ChIn(1) until C # $0D \CR\;
if C = $0A \LF\ then quit;
Line(I):= C;
I:= I+1;
];
Line(I):= 0;
PrintLn(Line);
]
zkl
File ff.zkl:
numLines:=File.stdin.readln().strip().toInt();
text:=File.stdin.readln(numLines);
text.apply(File.stdout.write);
- Output:
cat foo.txt | zkl ff hello hello world Pack my Box with 5 dozen liquor jugs