exec: Add TTYRows and TTYColumns properties to set TTY dimensions

src/basic/terminal-util.c

@@ -857,6 +857,39 @@ unsigned lines(void) {
         return cached_lines;
 }
 
+int terminal_set_size_fd(int fd, const char *ident, unsigned rows, unsigned cols) {
+        struct winsize ws;
+
+        if (rows == UINT_MAX && cols == UINT_MAX)
+                return 0;
+
+        if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
+                return log_debug_errno(errno,
+                                       "TIOCGWINSZ ioctl for getting %s size failed, not setting terminal size: %m",
+                                       ident ?: "TTY");
+
+        if (rows == UINT_MAX)
+                rows = ws.ws_row;
+        else if (rows > USHRT_MAX)
+                rows = USHRT_MAX;
+
+        if (cols == UINT_MAX)
+                cols = ws.ws_col;
+        else if (cols > USHRT_MAX)
+                cols = USHRT_MAX;
+
+        if (rows == ws.ws_row && cols == ws.ws_col)
+                return 0;
+
+        ws.ws_row = rows;
+        ws.ws_col = cols;
+
+        if (ioctl(fd, TIOCSWINSZ, &ws) < 0)
+                return log_debug_errno(errno, "TIOCSWINSZ ioctl for setting %s size failed: %m", ident ?: "TTY");
+
+        return 0;
+}
+
 /* intended to be used as a SIGWINCH sighandler */
 void columns_lines_cache_reset(int signum) {
         cached_columns = 0;

src/basic/terminal-util.h

@@ -120,6 +120,8 @@ int release_terminal(void);
 int terminal_vhangup_fd(int fd);
 int terminal_vhangup(const char *name);
 
+int terminal_set_size_fd(int fd, const char *ident, unsigned rows, unsigned cols);
+
 int chvt(int vt);
 
 int read_one_char(FILE *f, char *ret, usec_t timeout, bool *need_nl);