Simplify color & banner logic

client/comms.c

@@ -265,13 +265,6 @@ static void PacketResponseReceived(PacketResponseNG *packet) {
     // we got a packet, reset WaitForResponseTimeout timeout
     timeout_start_time = msclock();
 
-    bool filter_ansi = true;
-#if defined(__linux__) || (__APPLE__)
-    struct stat tmp_stat;
-    if ((fstat (STDOUT_FILENO, &tmp_stat) == 0) && (S_ISCHR (tmp_stat.st_mode)) && isatty(STDIN_FILENO))
-        filter_ansi = false;
-#endif
-
     switch (packet->cmd) {
         // First check if we are handling a debug message
         case CMD_DEBUG_PRINT_STRING: {
@@ -289,11 +282,11 @@ static void PacketResponseReceived(PacketResponseNG *packet) {
                 struct d *data = (struct d *)&packet->data.asBytes;
                 len = packet->length - sizeof(data->flag);
                 flag = data->flag;
-                memcpy_filter_ansi(s, data->buf, len, (flag & FLAG_ANSI) && filter_ansi);
+                memcpy(s, data->buf, len);
             } else {
                 len = MIN(packet->oldarg[0], USB_CMD_DATA_SIZE);
                 flag = packet->oldarg[1];
-                memcpy_filter_ansi(s, packet->data.asBytes, len, (flag & FLAG_ANSI) && filter_ansi);
+                memcpy(s, packet->data.asBytes, len);
             }
 
             if (flag & FLAG_LOG) {

client/proxmark3.c

@@ -438,9 +438,21 @@ int main(int argc, char *argv[]) {
         return 1;
     }
 
-    // ascii art
-    bool stdinOnPipe = !isatty(STDIN_FILENO);
-    if (!script_cmds_file && !stdinOnPipe)
+    session.supports_colors = false;
+    session.stdinOnTTY = isatty(STDIN_FILENO);
+    session.stdoutOnTTY = isatty(STDOUT_FILENO);
+#if defined(__linux__) || (__APPLE__)
+    // it's okay to use color if:
+    // * Linux or OSX
+    // * Not redirected to a file but printed to term
+    // For info, grep --color=auto is doing sth like this, plus test getenv("TERM") != "dumb":
+    //   struct stat tmp_stat;
+    //   if ((fstat (STDOUT_FILENO, &tmp_stat) == 0) && (S_ISCHR (tmp_stat.st_mode)) && isatty(STDIN_FILENO))
+    if (session.stdinOnTTY && session.stdoutOnTTY)
+        session.supports_colors = true;
+#endif
+    // ascii art only in interactive client
+    if (!script_cmds_file && !script_cmd && session.stdinOnTTY && session.stdoutOnTTY)
         showBanner();
 
     // Let's take a baudrate ok for real UART, USB-CDC & BT don't use that info anyway

client/ui.c

@@ -16,10 +16,7 @@
 #endif
 
 #include "ui.h"
-#if defined(__linux__) || (__APPLE__)
-#include <unistd.h>
-#include <sys/stat.h>
-#endif
+session_arg_t session;
 
 double CursorScaleFactor = 1;
 int PlotGridX = 0, PlotGridY = 0, PlotGridXdefault = 64, PlotGridYdefault = 64;
@@ -179,12 +176,7 @@ void PrintAndLog(const char *fmt, ...) {
     vsnprintf(buffer, sizeof(buffer), fmt, argptr);
     va_end(argptr);
 
-    bool filter_ansi = true;
-#if defined(__linux__) || (__APPLE__)
-    struct stat tmp_stat;
-    if ((fstat (STDOUT_FILENO, &tmp_stat) == 0) && (S_ISCHR (tmp_stat.st_mode)) && isatty(STDIN_FILENO))
-        filter_ansi = false;
-#endif
+    bool filter_ansi = !session.supports_colors;
     memcpy_filter_ansi(buffer2, buffer, sizeof(buffer), filter_ansi);
     printf("%s", buffer2);
     printf("          "); // cleaning prompt

client/ui.h

@@ -24,6 +24,14 @@
 #include <complex.h>
 #include "util.h"
 
+typedef struct {
+    bool stdinOnTTY;
+    bool stdoutOnTTY;
+    bool supports_colors;
+} session_arg_t;
+
+extern session_arg_t session;
+
 #ifndef M_PI
 #define M_PI 3.14159265358979323846264338327
 #endif