[PATCH] getdents.2: Use 'ssize_t' instead of 'int'

Alejandro Colomar
2020-10-28T22:11:39Z

The glibc wrapper for getdents64() uses ssize_t.
And let's use it also for getdents().
It makes more sense than int:
It's a count of bytes, and can report an error (-1).

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
---
man2/getdents.2 | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/man2/getdents.2 b/man2/getdents.2
index a187fbcef..d660f1bc1 100644
--- a/man2/getdents.2
+++ b/man2/getdents.2
@@ -33,13 +33,13 @@
getdents, getdents64 \- get directory entries
.SH SYNOPSIS
.nf
-.BI "int getdents(unsigned int " fd ", struct linux_dirent *" dirp ,
+.BI "ssize_t getdents(unsigned int " fd ", struct linux_dirent *" dirp ,
.BI " unsigned int " count );
.PP
.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
.B #include <dirent.h>
.PP
-.BI "int getdents64(unsigned int " fd ", struct linux_dirent64 *" dirp ,
+.BI "ssize_t getdents64(unsigned int " fd ", struct linux_dirent64 *" dirp ,
.BI " unsigned int " count );
.fi
.PP
@@ -266,6 +266,7 @@ inode# file type d_reclen d_off d_name
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/syscall.h>
+#include <sys/types.h>

#define handle_error(msg) \e
do { perror(msg); exit(EXIT_FAILURE); } while (0)
@@ -282,7 +283,8 @@ struct linux_dirent {
int
main(int argc, char *argv[])
{
- int fd, nread;
+ int fd;
+ ssize_t nread;
char buf[BUF_SIZE];
struct linux_dirent *d;
char d_type;
@@ -301,7 +303,7 @@ main(int argc, char *argv[])

printf("\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- nread=%d \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\en", nread);
printf("inode# file type d_reclen d_off d_name\en");
- for (int bpos = 0; bpos < nread;) {
+ for (ssize_t bpos = 0; bpos < nread;) {
d = (struct linux_dirent *) (buf + bpos);
printf("%8ld ", d\->d_ino);
d_type = *(buf + bpos + d\->d_reclen \- 1);
--
2.28.0