[hackers] [sbase] Use PRIO_{MIN,MAX} instead of NZERO || sin

[git]

commit 166bc3052e1e0813f6ff094f6429e3368f98f7bf
Author: sin <s...@2f30.org>
Date:   Mon Nov 17 15:01:43 2014 +0000

    Use PRIO_{MIN,MAX} instead of NZERO
    
    Some systems do not define NZERO.  NZERO seems to be an XSI extension
    and PRIO_{MIN,MAX} is not specified by POSIX but most relevant systems
    define it.

diff --git a/nice.c b/nice.c
index c4de430..8a48bf1 100644
--- a/nice.c
+++ b/nice.c
@@ -37,7 +37,7 @@ main(int argc, char *argv[])
        val += getpriority(PRIO_PROCESS, 0);
        if (errno != 0)
                weprintf("getpriority:");
-       val = MAX(-NZERO, MIN(val, NZERO - 1));
+       val = MAX(PRIO_MIN, MIN(val, PRIO_MAX));
        if (setpriority(PRIO_PROCESS, 0, val) != 0)
                weprintf("setpriority:");
 
diff --git a/renice.c b/renice.c
index 78ba233..feba155 100644
--- a/renice.c
+++ b/renice.c
@@ -105,7 +105,7 @@ renice(int which, int who, long adj)
                return 0;
        }
 
-       adj = MAX(-NZERO, MIN(adj, NZERO - 1));
+       adj = MAX(PRIO_MIN, MIN(adj, PRIO_MAX));
        if (setpriority(which, who, (int)adj) == -1) {
                fprintf(stderr, "can't set %d nice level: %s\n",
                        who, strerror(errno));