#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <ctype.h>
static bool isNumber(const char *s)
{
while (*s == ' ')
++s;
bool if_find_num = false;
if (*s == '-' || *s == '+')
++s;
while (isdigit(*s)) {
if_find_num = true;
++s;
}
if (*s == '.')
++s;
while (isdigit(*s)) {
if_find_num = true;
++s;
}
if (if_find_num == true && *s == 'e') {
++s;
if (*s == '+' || *s == '-')
++s;
if_find_num = false;
while (isdigit(*s)) {
if_find_num = true;
++s;
}
}
while (*s == ' ')
++s;
return *s == '\0' && if_find_num == true;
}
int main(int argc, char** argv)
{
if (argc != 2) {
fprintf(stderr, "Usage: ./test number\n");
exit(-1);
}
printf("%s\n", isNumber(argv[1]) ? "true" : "false");
return 0;
}
