usr/lib/learn/C/L5.2e

#print
(Section 1.5)
Write a program which copies its input to its output
doubling each character (i.e. each input character
is written twice on the output).  Compile and test
it.  Then type ready.  Don't forget

 \b#include <stdio.h>

at the beginning of your program, and

cc x.c -lS

to compile it.
#once #create Ref
hoboken harrison newark roseville avenue grove street
east orange brick church orange highland avenue
mountain station south orange maplewood millburn short hills
summit chatham madison convent station morristown
new providence murray hill berkeley heights
gillette stirling millington lyons basking ridge
bernardsville far hills peapack gladstone
#once #create Answer
hhoobbookkeenn  hhaarrrriissoonn  nneewwaarrkk  rroosseevviillllee  aavveennuuee  ggrroovvee  ssttrreeeett

eeaasstt  oorraannggee  bbrriicckk  cchhuurrcchh  oorraannggee  hhiigghhllaanndd  aavveennuuee

mmoouunnttaaiinn  ssttaattiioonn  ssoouutthh  oorraannggee  mmaapplleewwoooodd  mmiillllbbuurrnn  sshhoorrtt  hhiillllss

ssuummmmiitt  cchhaatthhaamm  mmaaddiissoonn  ccoonnvveenntt  ssttaattiioonn  mmoorrrriissttoowwnn

nneeww  pprroovviiddeennccee  mmuurrrraayy  hhiillll  bbeerrkkeelleeyy  hheeiigghhttss

ggiilllleettttee  ssttiirrlliinngg  mmiilllliinnggttoonn  llyyoonnss  bbaasskkiinngg  rriiddggee

bbeerrnnaarrddssvviillllee  ffaarr  hhiillllss  ppeeaappaacckk  ggllaaddssttoonnee

#user
a.out <Ref >xxx
#cmp Answer xxx
#succeed
/*      One way: */

 \b#include <stdio.h>

main()
{
        int c;

        while ((c = getchar()) != EOF) {
                putchar(c);
                putchar(c);
        }
}
#log
#next
5.1e 5
5.3e 2