feat: add is_terminal_attached syscall

template/docs/syscalls.md

@@ -32,6 +32,7 @@ void     exit(int code);                              // Terminate process (nore
 void     yield();                                     // Yield CPU to scheduler
 void     sleep_ms(uint64_t ms);                       // Sleep for milliseconds
 int      getpid();                                    // Get current process ID
+bool     terminal_attached();                         // Whether stdout is connected to a userspace terminal
 int      spawn(const char* path, const char* args);   // Spawn child, inheriting environment
 int      waitpid(int pid);                            // Wait for process to exit
 int      kill(int pid);                               // Kill a process

template/sysroot/include/Api/Syscall.hpp

@@ -240,6 +240,7 @@ namespace montauk::abi {
     static constexpr uint64_t SYS_SPAWN_ENV           = 173;
 
     static constexpr uint64_t SYS_LOG_WRITE           = 176;  // (logMessage) -> 0
+    static constexpr uint64_t SYS_TERMINAL_ATTACHED   = 177;  // () -> 1 when connected to a userspace terminal
 
     // Tunable parameters (for SYS_SDR_SETPARAM / SYS_SDR_GETPARAM).
     static constexpr int SDR_PARAM_FREQ        = 0;  // center frequency, Hz

template/sysroot/include/libc/montauk.h

@@ -69,7 +69,7 @@ extern "C" {
 #define MTK_SYS_TERMSCALE          43
 #define MTK_SYS_RESOLVE            44
 #define MTK_SYS_GETRANDOM          45
-#define MTK_SYS_LOG               46
+#define MTK_SYS_LOG                46
 #define MTK_SYS_MOUSESTATE         47
 #define MTK_SYS_SETMOUSEBOUNDS     48
 #define MTK_SYS_SPAWN_REDIR        49
@@ -200,6 +200,7 @@ extern "C" {
 #define MTK_SYS_SETSESSION         174
 #define MTK_SYS_KILLSESSION        175
 #define MTK_SYS_LOG_WRITE          176
+#define MTK_SYS_TERMINAL_ATTACHED  177
 /* @SYSCALLS-END */
 
 #define MTK_SOCK_TCP 1
@@ -419,6 +420,10 @@ static inline int mtk_getpid(void) {
     return (int)_mtk_syscall0(MTK_SYS_GETPID);
 }
 
+static inline int mtk_terminal_attached(void) {
+    return (int)_mtk_syscall0(MTK_SYS_TERMINAL_ATTACHED) != 0;
+}
+
 static inline int mtk_spawn(const char *path, const char *args) {
     return (int)_mtk_syscall2(MTK_SYS_SPAWN, (long)path, (long)args);
 }

template/sysroot/include/montauk/syscall.h

@@ -438,6 +438,11 @@ namespace montauk {
         return syscall1(montauk::abi::SYS_LOG_WRITE, (uint64_t)logMessage);
     }
 
+    // True when stdout is connected to a redirected userspace terminal.
+    inline bool terminal_attached() {
+        return syscall0(montauk::abi::SYS_TERMINAL_ATTACHED) != 0;
+    }
+
     // I/O redirection
     inline int spawn_redir(const char* path, const char* args = nullptr) {
         return (int)syscall2(montauk::abi::SYS_SPAWN_REDIR, (uint64_t)path, (uint64_t)args);