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-rw-r--r--lib/libc/stdlib/qsort.342
1 files changed, 41 insertions, 1 deletions
diff --git a/lib/libc/stdlib/qsort.3 b/lib/libc/stdlib/qsort.3
index 0f7ef73..f34d260 100644
--- a/lib/libc/stdlib/qsort.3
+++ b/lib/libc/stdlib/qsort.3
@@ -32,7 +32,7 @@
.\" @(#)qsort.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
-.Dd September 30, 2003
+.Dd February 20, 2013
.Dt QSORT 3
.Os
.Sh NAME
@@ -205,6 +205,46 @@ functions
return no value.
.Pp
.Rv -std heapsort mergesort
+.Sh EXAMPLES
+A sample program that sorts an array of
+.Vt int
+values in place using
+.Fn qsort ,
+and then prints the sorted array to standard output is:
+.Bd -literal
+#include <stdio.h>
+#include <stdlib.h>
+
+/*
+ * Custom comparison function that can compare 'int' values through pointers
+ * passed by qsort(3).
+ */
+static int
+int_compare(const void *p1, const void *p2)
+{
+ int left = *(const int *)p1;
+ int right = *(const int *)p2;
+
+ return ((left > right) - (left < right));
+}
+
+/*
+ * Sort an array of 'int' values and print it to standard output.
+ */
+int
+main(void)
+{
+ int int_array[] = { 4, 5, 9, 3, 0, 1, 7, 2, 8, 6 };
+ const size_t array_size = sizeof(int_array) / sizeof(int_array[0]);
+ size_t k;
+
+ qsort(&int_array, array_size, sizeof(int_array[0]), int_compare);
+ for (k = 0; k < array_size; k++)
+ printf(" %d", int_array[k]);
+ puts("");
+ return (EXIT_SUCCESS);
+}
+.Ed
.Sh COMPATIBILITY
Previous versions of
.Fn qsort
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