config/git: import suckless sbase

i currently use the output of sha512sum in several
places of xbmk, which is a bit unreliable in case
output changes.

other cases where i use util outputs in variables
are probably reliable, because i'm using mostly
posix utilities in those.

to mitigate this, i now import suckless sbase, which
has a reasonable sha512sum implementation.

*every* binary it builds is being placed in build.list,
because i'll probably start using more of them.

for example, i may start modifying the "date"
implementation, adding the GNU-specific options that
i need as mentioned on init.sh

i'm importing it in util/ because the sha512sum
util is needed for verifying project sources, so
if sbase itself is a "project source", that means
we can into a chicken and egg bootstrapping problem.

this is sbase at revision:
055cc1ae1b3a13c3d8f25af0a4a3316590efcd48

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/sbase/renice.c

@@ -0,0 +1,93 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/resource.h>
+
+#include <errno.h>
+#include <pwd.h>
+#include <stdlib.h>
+
+#include "util.h"
+
+#ifndef PRIO_MIN
+#define PRIO_MIN -NZERO
+#endif
+
+#ifndef PRIO_MAX
+#define PRIO_MAX (NZERO-1)
+#endif
+
+static int
+renice(int which, int who, long adj)
+{
+	errno = 0;
+	adj += getpriority(which, who);
+	if (errno) {
+		weprintf("getpriority %d:", who);
+		return 0;
+	}
+
+	adj = MAX(PRIO_MIN, MIN(adj, PRIO_MAX));
+	if (setpriority(which, who, (int)adj) < 0) {
+		weprintf("setpriority %d:", who);
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+usage(void)
+{
+	eprintf("usage: %s -n num [-g | -p | -u] id ...\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	const char *adj = NULL;
+	long val;
+	int which = PRIO_PROCESS, ret = 0;
+	struct passwd *pw;
+	int who;
+
+	ARGBEGIN {
+	case 'n':
+		adj = EARGF(usage());
+		break;
+	case 'g':
+		which = PRIO_PGRP;
+		break;
+	case 'p':
+		which = PRIO_PROCESS;
+		break;
+	case 'u':
+		which = PRIO_USER;
+		break;
+	default:
+		usage();
+	} ARGEND
+
+	if (!argc || !adj)
+		usage();
+
+	val = estrtonum(adj, PRIO_MIN, PRIO_MAX);
+	for (; *argv; argc--, argv++) {
+		if (which == PRIO_USER) {
+			errno = 0;
+			if (!(pw = getpwnam(*argv))) {
+				if (errno)
+					weprintf("getpwnam %s:", *argv);
+				else
+					weprintf("getpwnam %s: no user found\n", *argv);
+				ret = 1;
+				continue;
+			}
+			who = pw->pw_uid;
+		} else {
+			who = estrtonum(*argv, 1, INT_MAX);
+		}
+		if (!renice(which, who, val))
+			ret = 1;
+	}
+
+	return ret;
+}