#include "apue.h" #include #include static void pr_sysconf(char *, int); static void pr_pathconf(char *, char *, int); int main(int argc, char *argv[]) { if (argc != 2) err_quit("usage: a.out "); #ifdef ARG_MAX printf("ARG_MAX defined to be %d\n", ARG_MAX+0); #else printf("no symbol for ARG_MAX\n"); #endif #ifdef _SC_ARG_MAX pr_sysconf("ARG_MAX =", _SC_ARG_MAX); #else printf("no symbol for _SC_ARG_MAX\n"); #endif /* similar processing for all the rest of the sysconf symbols... */ #ifdef MAX_CANON printf("MAX_CANON defined to be %d\n", MAX_CANON+0); #else printf("no symbol for MAX_CANON\n"); #endif #ifdef _PC_MAX_CANON pr_pathconf("MAX_CANON =", argv[1], _PC_MAX_CANON); #else printf("no symbol for _PC_MAX_CANON\n"); #endif /* similar processing for all the rest of the pathconf symbols... */ exit(0); } static void pr_sysconf(char *mesg, int name) { long val; fputs(mesg, stdout); errno = 0; if ((val = sysconf(name)) < 0) { if (errno != 0) { if (errno == EINVAL) fputs(" (not supported)\n", stdout); else err_sys("sysconf error"); } else { fputs(" (no limit)\n", stdout); } } else { printf(" %ld\n", val); } } static void pr_pathconf(char *mesg, char *path, int name) { long val; fputs(mesg, stdout); errno = 0; if ((val = pathconf(path, name)) < 0) { if (errno != 0) { if (errno == EINVAL) fputs(" (not supported)\n", stdout); else err_sys("pathconf error, path = %s", path); } else { fputs(" (no limit)\n", stdout); } } else { printf(" %ld\n", val); } }