banan-os/userspace/programs/sleep/main.cpp

39 lines
653 B
C++

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
int usage(char* argv0, int ret)
{
FILE* fp = (ret == 0) ? stdout : stderr;
fprintf(fp, "usage: %s SECONDS\n", argv0);
return ret;
}
int main(int argc, char** argv)
{
if (argc != 2)
return usage(argv[0], 1);
if (strlen(argv[1]) > 9)
{
fprintf(stderr, "SECONDS argument too large\n");
return usage(argv[0], 1);
}
int seconds = 0;
const char* ptr = argv[1];
while (*ptr)
{
if (!isdigit(*ptr))
{
fprintf(stderr, "invalid SECONDS argument\n");
return usage(argv[0], 1);
}
seconds = (seconds * 10) + (*ptr - '0');
ptr++;
}
sleep(seconds);
}