intarg, longarg, shortarg - parse integer argument or ask user

#include <ctype.h>
#include <stdio.h>

int intarg (ptr,brk,prompt,min,max,defalt);
const char **ptr,*brk,*prompt;
int min,max,defalt;

long longarg (ptr,brk,prompt,min,max,defalt);
const char **ptr,*brk,*prompt;
long min,max,defalt;

short shortarg (ptr,brk,prompt,min,max,defalt);
const char **ptr,*brk,*prompt;
short min,max,defalt;

Intarg, longarg, and shortarg attempt to parse an argument from a
string, passing the string pointer ptr and the break character set
brk to the nxtarg(3) routine. If there is an argument parsed, and
it is a legal integer whose value is between min and max, then its
value is returned by intarg, longarg, or shortarg. If there is no
argument, or it is not a valid integer, or the value is out of
range, then an error message is printed and the remaining arguments
are passed to getint(3), getlong(3), or getshort(3). The resulting
value is then returned by intarg, longarg, or shortarg.

Intarg, longarg, and shortarg are especially useful for parsing
integer values from argument lists in programs using the command
interpreter, ci(3).

nxtarg(3), getint(3), getlong(3), getshort(3), ci(3)