commit fce31870886ca101bf359508f0ce6be076433da4
author Elliott Hughes <enh@google.com> Tue Jul 28 12:06:23 2020 -0700
committer Elliott Hughes <enh@google.com> Tue Jul 28 12:12:20 2020 -0700
tree 2a11e57c4def6ece3d6bb422d183a9ec7edb0b08
parent 9c6d60d073db079a87fbeb5de3e72ac12838a480

Cleanup for #inclusivefixit.

This was initially just to try on "pty" and "tty" for size, while
discussing with other projects to try to align on vocabulary, but -- in
the implemention and tests at least -- but these work out so well that
I'm tempted to go with them anyway if we can't come to a concensus. We
can always come back and change them again later.

What I really like is that you pass the pty to functions like ptsname()
and grantpt() with a 'p' in the name, and the tty to functions like
ttyname() and tcsetattr() with just 't's.

The use of "parent" and "child" in forkpty() seems helpful too.

Also fix the documentation of forkpty(), which wasn't quite right.

Test: treehugger
Change-Id: Ic010c4b669f6528591c653e3701f4e41e0d0df9e

libc/bionic/pty.cpp

diff --git a/libc/bionic/pty.cpp b/libc/bionic/pty.cpp
index 71e14d9..c0e2721 100644
--- a/libc/bionic/pty.cpp
+++ b/libc/bionic/pty.cpp
@@ -112,14 +112,14 @@
   return ioctl(fd, TIOCSPTLCK, &unlock);
 }
 
-int openpty(int* master, int* slave, char* name, const termios* t, const winsize* ws) {
-  *master = getpt();
-  if (*master == -1) {
+int openpty(int* pty, int* tty, char* name, const termios* t, const winsize* ws) {
+  *pty = getpt();
+  if (*pty == -1) {
     return -1;
   }
 
-  if (grantpt(*master) == -1 || unlockpt(*master) == -1) {
-    close(*master);
+  if (grantpt(*pty) == -1 || unlockpt(*pty) == -1) {
+    close(*pty);
     return -1;
   }
 
@@ -127,54 +127,54 @@
   if (name == nullptr) {
     name = buf;
   }
-  if (ptsname_r(*master, name, sizeof(buf)) != 0) {
-    close(*master);
+  if (ptsname_r(*pty, name, sizeof(buf)) != 0) {
+    close(*pty);
     return -1;
   }
 
-  *slave = open(name, O_RDWR|O_NOCTTY);
-  if (*slave == -1) {
-    close(*master);
+  *tty = open(name, O_RDWR | O_NOCTTY);
+  if (*tty == -1) {
+    close(*pty);
     return -1;
   }
 
   if (t != nullptr) {
-    tcsetattr(*slave, TCSAFLUSH, t);
+    tcsetattr(*tty, TCSAFLUSH, t);
   }
   if (ws != nullptr) {
-    ioctl(*slave, TIOCSWINSZ, ws);
+    ioctl(*tty, TIOCSWINSZ, ws);
   }
 
   return 0;
 }
 
-int forkpty(int* amaster, char* name, const termios* t, const winsize* ws) {
-  int master;
-  int slave;
-  if (openpty(&master, &slave, name, t, ws) == -1) {
+int forkpty(int* parent_pty, char* child_tty_name, const termios* t, const winsize* ws) {
+  int pty;
+  int tty;
+  if (openpty(&pty, &tty, child_tty_name, t, ws) == -1) {
     return -1;
   }
 
   pid_t pid = fork();
   if (pid == -1) {
-    close(master);
-    close(slave);
+    close(pty);
+    close(tty);
     return -1;
   }
 
   if (pid == 0) {
     // Child.
-    *amaster = -1;
-    close(master);
-    if (login_tty(slave) == -1) {
+    *parent_pty = -1;
+    close(pty);
+    if (login_tty(tty) == -1) {
       _exit(1);
     }
     return 0;
   }
 
   // Parent.
-  *amaster = master;
-  close(slave);
+  *parent_pty = pty;
+  close(tty);
   return pid;
 }