系统编译限制

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>

static void pr_sysconf(char *msg, int name);
static void pr_pathconf(char *msg, char *path, int name);

int main(int argc, char *argv[])
{
    if(argc != 2)
    {
        printf("args no enough\n");
        exit(1);
    }
    #ifdef ARG_MAX
    printf("ARG_MAX defined to be %d\n",ARG_MAX + 0);
    #else
    printf("no simble for ARG_MAX\n");
    #endif

    #ifdef _SC_ARG_MAX
    pr_sysconf("arg_MAX = ", _SRC_ARG_MAX);
    #else
    printf("no simbel");
    #endif

    #ifdef _PC_MAX_CANON
    pr_pathconf("max_CANON : ", argv[1], _PC_MAX_CANON);
    #else
    printf("no the sible");
    #endif

    return 0;
}
static void pr_sysconf(char *msg, int name)
{
    long val;
    fputs(msg, stdout);
    errno = 0;
    if((val = sysconf(name)) < 0)
    {
        if(errno != 0)
        {
            if(errno == EINVAL)
                fputs("not suport\n", stdout);
            else
                printf("sysconf error\n");
        }
        else
            printf("no limit\n");
    }
    else
        printf("%ld\n", val);
}

static void pr_pathconf(char *msg, char *path, int name)
{
    long val;
    errno = 0;
    if((val = pathconf(path, name)) < 0)
    {
        if(errno != 0)
        {
            if(errno == EINVAL)
                fputs("not suport\n", stdout);
            else
                printf("sysconf error\n");
        }
        else
            printf("no limit\n");
    }
    else
        printf("%ld\n", val);
}