From 18da0c28ad9bb0da713b80b5c6fd72741f3fcb2f Mon Sep 17 00:00:00 2001
From: h2-addad <hamza2.addad@live.uwe.ac.uk>
Date: Sun, 16 Jul 2023 00:59:43 +0000
Subject: [PATCH] Update
---
src/examples/lineup.c | 46 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 src/examples/lineup.c
diff --git a/src/examples/lineup.c b/src/examples/lineup.c
new file mode 100644
index 0000000..cff28d8
--- /dev/null
+++ b/src/examples/lineup.c
@@ -0,0 +1,46 @@
+/* lineup.c
+
+ Converts a file to uppercase in-place.
+
+ Incidentally, another way to do this while avoiding the seeks
+ would be to open the input file, then remove() it and reopen
+ it under another handle. Because of Unix deletion semantics
+ this works fine. */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <syscall.h>
+
+int
+main (int argc, char *argv[])
+{
+ char buf[1024];
+ int handle;
+
+ if (argc != 2)
+ exit (1);
+
+ handle = open (argv[1]);
+ if (handle < 0)
+ exit (2);
+
+ for (;;)
+ {
+ int n, i;
+
+ n = read (handle, buf, sizeof buf);
+ if (n <= 0)
+ break;
+
+ for (i = 0; i < n; i++)
+ buf[i] = toupper ((unsigned char) buf[i]);
+
+ seek (handle, tell (handle) - n);
+ if (write (handle, buf, n) != n)
+ printf ("write failed\n");
+ }
+
+ close (handle);
+
+ return EXIT_SUCCESS;
+}
--
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