Add basic linux termios implementation

lib/std/c.zig

@@ -119,6 +119,8 @@ pub extern "c" fn getrusage(who: c_int, usage: *rusage) c_int;
 pub extern "c" fn sysctl(name: [*]const c_int, namelen: c_uint, oldp: ?*c_void, oldlenp: ?*usize, newp: ?*c_void, newlen: usize) c_int;
 pub extern "c" fn sysctlbyname(name: [*:0]const u8, oldp: ?*c_void, oldlenp: ?*usize, newp: ?*c_void, newlen: usize) c_int;
 pub extern "c" fn sysctlnametomib(name: [*:0]const u8, mibp: ?*c_int, sizep: ?*usize) c_int;
+pub extern "c" fn tcgetattr(fd: fd_t, termios_p: *termios) c_int;
+pub extern "c" fn tcsetattr(fd: fd_t, optional_action: TCSA, termios_p: *const termios) c_int;
 
 pub extern "c" fn gethostname(name: [*]u8, len: usize) c_int;
 pub extern "c" fn bind(socket: fd_t, address: ?*const sockaddr, address_len: socklen_t) c_int;

lib/std/os.zig

@@ -3327,3 +3327,35 @@ pub fn getrusage(who: i32) rusage {
         else => unreachable,
     }
 }
+
+pub const TermiosGetError = error{
+    NotATerminal,
+} || UnexpectedError;
+
+pub fn tcgetattr(handle: fd_t) TermiosGetError!termios {
+    var term: termios = undefined;
+    switch (errno(system.tcgetattr(handle, &term))) {
+        0 => return term,
+        EBADF => unreachable,
+        ENOTTY => return error.NotATerminal,
+        else => |err| return unexpectedErrno(err),
+    }
+}
+
+pub const TermiosSetError = TermiosGetError || error{
+    ProcessOrphaned,
+};
+
+pub fn tcsetattr(handle: fd_t, optional_action: TCSA, termios_p: termios) TermiosSetError!void {
+    while (true) {
+        switch (errno(system.tcsetattr(handle, optional_action, &termios_p))) {
+            0 => return,
+            EBADF => unreachable,
+            EINTR => continue,
+            EINVAL => unreachable,
+            ENOTTY => return error.NotATerminal,
+            EIO => return error.ProcessOrphaned,
+            else => |err| return unexpectedErrno(err),
+        }
+    }
+}

lib/std/os/bits/linux.zig

@@ -1515,3 +1515,77 @@ pub const rusage = extern struct {
     nivcsw: isize,
     __reserved: [16]isize = [1]isize{0} ** 16,
 };
+
+pub const cc_t = u8;
+pub const speed_t = u32;
+pub const tcflag_t = u32;
+
+pub const NCCS = 32;
+
+pub const IGNBRK = 1;
+pub const BRKINT = 2;
+pub const IGNPAR = 4;
+pub const PARMRK = 8;
+pub const INPCK = 16;
+pub const ISTRIP = 32;
+pub const INLCR = 64;
+pub const IGNCR = 128;
+pub const ICRNL = 256;
+pub const IUCLC = 512;
+pub const IXON = 1024;
+pub const IXANY = 2048;
+pub const IXOFF = 4096;
+pub const IMAXBEL = 8192;
+pub const IUTF8 = 16384;
+
+pub const OPOST = 1;
+pub const OLCUC = 2;
+pub const ONLCR = 4;
+pub const OCRNL = 8;
+pub const ONOCR = 16;
+pub const ONLRET = 32;
+pub const OFILL = 64;
+pub const OFDEL = 128;
+pub const VTDLY = 16384;
+pub const VT0 = 0;
+pub const VT1 = 16384;
+
+pub const CSIZE = 48;
+pub const CS5 = 0;
+pub const CS6 = 16;
+pub const CS7 = 32;
+pub const CS8 = 48;
+pub const CSTOPB = 64;
+pub const CREAD = 128;
+pub const PARENB = 256;
+pub const PARODD = 512;
+pub const HUPCL = 1024;
+pub const CLOCAL = 2048;
+
+pub const ISIG = 1;
+pub const ICANON = 2;
+pub const ECHO = 8;
+pub const ECHOE = 16;
+pub const ECHOK = 32;
+pub const ECHONL = 64;
+pub const NOFLSH = 128;
+pub const TOSTOP = 256;
+pub const IEXTEN = 32768;
+
+pub const TCSA = extern enum(usize) {
+    NOW,
+    DRAIN,
+    FLUSH,
+    _,
+};
+
+pub const termios = extern struct {
+    iflag: tcflag_t,
+    oflag: tcflag_t,
+    cflag: tcflag_t,
+    lflag: tcflag_t,
+    line: cc_t,
+    cc: [NCCS]cc_t,
+    ispeed: speed_t,
+    ospeed: speed_t,
+};

lib/std/os/linux.zig

@@ -1061,6 +1061,14 @@ pub fn getrusage(who: i32, usage: *rusage) usize {
     return syscall2(SYS_getrusage, @bitCast(usize, @as(isize, who)), @ptrToInt(usage));
 }
 
+pub fn tcgetattr(fd: fd_t, termios_p: *termios) usize {
+    return syscall3(SYS_ioctl, @bitCast(usize, @as(isize, fd)), TCGETS, @ptrToInt(termios_p));
+}
+
+pub fn tcsetattr(fd: fd_t, optional_action: TCSA, termios_p: *const termios) usize {
+    return syscall3(SYS_ioctl, @bitCast(usize, @as(isize, fd)), TCSETS + @enumToInt(optional_action), @ptrToInt(termios_p));
+}
+
 test "" {
     if (builtin.os == .linux) {
         _ = @import("linux/test.zig");