A program to remove those ugly CONTROL-M s

/* clean.c -- Given as command line parameter a filename,
*            it removes from that file all occurrences of ^M
*            If 'clean' is the executable image of this
*            program, you can use it as follows:
*                 % clean dirtyfile > cleanfile
*/

#include <stdio.h>
#define CONTROLM 13

int main(int argc, char *argv[]){
char c;
FILE *fd;

if(argc!=2){
printf("Usage: %s filename\n", argv[0]);
exit(0);
}
if((fd = fopen(argv[1],"r"))==NULL){
perror("fopen");
exit(1);
}
while((c=getc(fd))!=EOF)
if (c!=CONTROLM)
putchar(c);
fclose(fd);
}