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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
commit464df1d5e5ab1322e2dd0a7796939fff1aeefa9a (patch)
tree6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /lib/e2p/percent.c
parentInitial commit. (diff)
downloade2fsprogs-464df1d5e5ab1322e2dd0a7796939fff1aeefa9a.tar.xz
e2fsprogs-464df1d5e5ab1322e2dd0a7796939fff1aeefa9a.zip
Adding upstream version 1.47.0.upstream/1.47.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/e2p/percent.c')
-rw-r--r--lib/e2p/percent.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/e2p/percent.c b/lib/e2p/percent.c
new file mode 100644
index 0000000..e340cd7
--- /dev/null
+++ b/lib/e2p/percent.c
@@ -0,0 +1,67 @@
+/*
+ * percent.c - Take percentage of a number
+ *
+ * Copyright (C) 2006 Theodore Ts'o <tytso@mit.edu>
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include "e2p.h"
+
+#include <stdlib.h>
+
+/*
+ * We work really hard to calculate this accurately, while avoiding
+ * an overflow. "Is there a hyphen in anal-retentive?" :-)
+ */
+unsigned int e2p_percent(int percent, unsigned int base)
+{
+ unsigned int mask = ~((1 << (sizeof(unsigned int) - 1) * 8) - 1);
+
+ if (!percent)
+ return 0;
+ if (100 % percent == 0)
+ return base / (100 / percent);
+ if (mask & base)
+ return (base / 100) * percent;
+ return base * percent / 100;
+}
+
+#ifdef DEBUG
+#include <unistd.h>
+#include <stdio.h>
+
+main(int argc, char **argv)
+{
+ unsigned int base;
+ int percent;
+ char *p;
+ int log_block_size = 0;
+
+ if (argc != 3) {
+ fprintf(stderr, "Usage: %s percent base\n", argv[0]);
+ exit(1);
+ }
+
+ percent = strtoul(argv[1], &p, 0);
+ if (p[0] && p[1]) {
+ fprintf(stderr, "Bad percent: %s\n", argv[1]);
+ exit(1);
+ }
+
+ base = strtoul(argv[2], &p, 0);
+ if (p[0] && p[1]) {
+ fprintf(stderr, "Bad base: %s\n", argv[2]);
+ exit(1);
+ }
+
+ printf("%d percent of %u is %u.\n", percent, base,
+ e2p_percent(percent, base));
+
+ exit(0);
+}
+#endif