From: Nathan Wagner <nw@hydaspes.if.org>
Date: Sat, 25 Apr 2015 23:25:47 +0000 (+0000)
Subject: implemented nice
X-Git-Url: https://pd.if.org/git/?p=pdutils;a=commitdiff_plain;h=252f8cd3b8783b1b74f3438ae0d771ec0a192a87

implemented nice
---

diff --git a/utils/nice/nice.c b/utils/nice/nice.c
new file mode 100644
index 0000000..7aab5b2
--- /dev/null
+++ b/utils/nice/nice.c
@@ -0,0 +1,90 @@
+#define _POSIX_C_SOURCE 200809L
+#define _XOPEN_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+
+/* Public domain by Nathan Wagner */
+
+/* reads a long from a string.  returns -1 if completely
+ * read, number of characters read otherwise,
+ * or zero if it can't read a string
+ * clears errno, which may be reset again by strtol()
+ */
+static int readint(char *s, long *i) {
+	long val;
+	char *end;
+	errno = 0;
+	val = strtol(s, &end, 10);
+
+	/* Check for various possible errors */
+
+	if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
+			|| (errno != 0 && val == 0)) {
+		perror("strtol");
+		return 0;
+	}
+
+	if (end == s) {
+		fprintf(stderr, "No digits were found\n");
+		return 0;
+	}
+
+	/* If we got here, strtol() successfully parsed a number */
+
+	*i = val;
+
+	if (*end != '\0') {
+	 	/* Not necessarily an error... */
+		/* printf("Further characters after number: %s\n", endptr); */
+		return end - s;
+	}
+
+	return -1;
+}
+
+static void usage(void) {
+	fprintf(stderr, "usage: nice [-n increment] utility [argument...]\n");
+	exit(1);
+}
+
+int main(int ac, char *av[]) {
+	int arg;
+	arg = 1;
+	long nval;
+	if (arg < ac && !strcmp(av[arg], "-n")) {
+		char *s = 0;
+		if (av[arg][2]) {
+			s = av[arg]+2;
+		} else if (++arg < ac) {
+			s = av[arg];
+		}
+		if (s && (readint(s, &nval) == -1)) {
+			nice((int)nval);
+			arg++;
+		} else {
+			usage();
+		}
+	}
+
+	if (arg < ac) {
+		execvp(av[arg], &av[arg]);
+		switch (errno) {
+			case ENOENT:
+				fprintf(stderr, "nice: ");
+				perror(av[arg]);
+			       	return 127;
+			default:
+				fprintf(stderr, "nice: ");
+				perror(av[arg]);
+				return 126;
+		}
+	} else {
+		usage();
+	}
+
+	return 1;
+}