nedko
/
termsize
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

termsize.c: Check return values of write() and read() calls 

While error and short read or write conditions with so small buffers are hard to impossible to trigger,
Checking the values is proper formally so was the warning from the compiler
This commit is contained in:
Nedko Arnaudov 2023-08-17 03:06:35 +03:00
parent 3d37f6d7f9
commit 2372fc41a8
1 changed files with 26 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
termsize.c
View File

@ -15,9 +15,9 @@
#include <stdbool.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
int fd;
const char * cmd;
char buf[256];
struct curpos
@ -26,20 +26,41 @@ struct curpos
int col;
};
void write_asciiz(const char * str)
{
ssize_t sret;
size_t len;
len = strlen(str);
loop:
sret = write(fd, str, len);
if (sret == -1) abort();
str += (size_t)sret;
len -= (size_t)sret;
if (len > 0) goto loop;
}
void get_cursor_position(struct curpos * pos)
{
int i;
char * p;
ssize_t sret;
cmd = "\033[6n";
write(fd, cmd, strlen(cmd));
write_asciiz("\033[6n");
i = 0;
loop:
if (i == sizeof(buf)) abort();
read(fd, buf + i, 1);
sret = read(fd, buf + i, 1);
if (sret == -1)
{
if (errno == EINTR) goto loop;
abort();
}
if (sret == 0) goto loop;
if (sret != 1) abort();
if (buf[i] == 'R')
{
buf[i] = 0;
@ -61,7 +82,7 @@ loop:
void set_cursor_position(const struct curpos * pos)
{
sprintf(buf, "\033[%d;%dH", pos->row, pos->col);
write(fd, buf, strlen(buf));
write_asciiz(buf);
}
void get_terminal_size(struct curpos * size)
@ -82,7 +103,6 @@ int main(void)
{
struct termios tty_save;
struct termios tty;
const char * cmd;
struct curpos size;
struct winsize winsize;