what\'s wrong with this programme?

I follow the \"button test \" source code given by ken,however I pushed several times to change the value of \"numclicks\",the I find one place maybe wrong,I changed some codeS in it as follow:

while (read (fd, buf, 1) != 0) {

if (buf[0] == \'1\') {

numclicks += 1;

printf (\"The button has been pushed %d times.\\n\", numclicks);

}

}

It\'s still takes several pushes to make \"numclicks\" increased by one.I don\'t know what\'s the matter.

code given by ken:

# include <stdio.h># include <unistd.h># include <fcntl.h># include <stdlib.h>

/* open /dev/button device for blocked reading

* whenever button is pressed,

* display number of times button was pressed since startup

*/

int

main (int argc, char* argv[])

{

int fd;

char path[] = \"/dev/button\";

int numclicks = 0;

char buf[1];

fd = open (path, O_RDONLY);

if (fd < 0) {

/* error occurred */

perror (\"open\");

exit (EXIT_FAILURE);

} else {

printf (\"opened %s\\n\", path);

}

/* file is now open for reading... do your stuff... */

while (read (fd, buf, 1) != 0) {

if (buf[0] == \&#39;1\&#39;) {

numclicks += 1;

}

printf (\"The button has been pushed %d times.\\n\", numclicks);

}

if (close (fd) < 0) {

perror (\"close\");

exit (EXIT_FAILURE);

} else {

printf (\"closed %s\\n\", path);

}

exit (EXIT_SUCCESS);

}