tStat each file and mmap(3) only as much as is really needed - catpoint - Catpoint simple presenting software.
(HTM) git clone git://r-36.net/catpoint
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---
(DIR) commit 7f4f52730310c65d30761a75ded86e2d82863298
(DIR) parent 78504360bf7518b5f7caadcf34ecb22187bdeeb8
(HTM) Author: Ekkie <ekkie@envs.net>
Date: Mon, 4 May 2020 12:51:49 +0200
Stat each file and mmap(3) only as much as is really needed
Signed-off-by: Christoph Lohmann <20h@r-36.net>
Diffstat:
catpoint.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
---
(DIR) diff --git a/catpoint.c b/catpoint.c
t@@ -1,6 +1,7 @@
/* $Id: catpoint.c,v 1.2 2013/03/28 12:00:48 lostd Exp $ */
#include <sys/types.h>
+#include <sys/stat.h>
#include <sys/mman.h>
#include <err.h>
t@@ -42,6 +43,7 @@ int
main(int argc, char *argv[])
{
int c, i, fd;
+ struct stat statbuf;
if (argc == 1)
errx(1, "usage: %s file ...", argv[0]);
t@@ -59,7 +61,9 @@ main(int argc, char *argv[])
fd = open(argv[i], O_RDONLY, 0);
if (fd == -1)
err(1, "open: %s", argv[i]);
- p[i] = mmap(NULL, 0x1000, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (fstat(fd, &statbuf) < 0)
+ err(1, "fstat: %s", argv[i]);
+ p[i] = mmap(NULL, statbuf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (p[i] == MAP_FAILED)
err(1, "mmap");
close(fd);