Provide a new result value, TERMKEY_RES_ERROR to indicate an IO error - preserve errno

demo.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <getopt.h>
+#include <errno.h>
 
 #include "termkey.h"
 
@@ -44,6 +45,7 @@ int main(int argc, char *argv[])
     printf("\e[?%dhMouse mode active\n", mouse);
 
   while((ret = termkey_waitkey(tk, &key)) != TERMKEY_RES_EOF) {
+    if(ret == TERMKEY_RES_KEY) {
       termkey_strfkey(tk, buffer, sizeof buffer, &key, format);
       printf("%s\n", buffer);
 
@@ -52,6 +54,14 @@ int main(int argc, char *argv[])
          (key.code.codepoint == 'C' || key.code.codepoint == 'c'))
         break;
     }
+    else if(ret == TERMKEY_RES_ERROR) {
+      if(errno != EINTR) {
+        perror("termkey_waitkey");
+        break;
+      }
+      printf("Interrupted by signal\n");
+    }
+  }
 
   if(mouse)
     printf("\e[?%dlMouse mode deactivated\n", mouse);

termkey.c

@@ -607,6 +607,7 @@ static TermKeyResult peekkey(TermKey *tk, TermKeyKey *key, int force, size_t *nb
 
       /* fallthrough */
     case TERMKEY_RES_EOF:
+    case TERMKEY_RES_ERROR:
       return ret;
 
     case TERMKEY_RES_AGAIN:
@@ -673,6 +674,7 @@ static TermKeyResult peekkey_simple(TermKey *tk, TermKeyKey *key, int force, siz
       case TERMKEY_RES_NONE:
       case TERMKEY_RES_EOF:
       case TERMKEY_RES_AGAIN:
+      case TERMKEY_RES_ERROR:
         break;
     }
 
@@ -821,10 +823,13 @@ TermKeyResult termkey_waitkey(TermKey *tk, TermKeyKey *key)
     switch(ret) {
       case TERMKEY_RES_KEY:
       case TERMKEY_RES_EOF:
+      case TERMKEY_RES_ERROR:
         return ret;
 
       case TERMKEY_RES_NONE:
-        termkey_advisereadable(tk);
+        ret = termkey_advisereadable(tk);
+        if(ret == TERMKEY_RES_ERROR)
+          return ret;
         break;
 
       case TERMKEY_RES_AGAIN:
@@ -839,13 +844,17 @@ TermKeyResult termkey_waitkey(TermKey *tk, TermKeyKey *key)
           fd.fd = tk->fd;
           fd.events = POLLIN;
 
-          poll(&fd, 1, tk->waittime);
+          int pollret = poll(&fd, 1, tk->waittime);
+          if(pollret == -1)
+            return TERMKEY_RES_ERROR;
 
           if(fd.revents & (POLLIN|POLLHUP|POLLERR))
             ret = termkey_advisereadable(tk);
           else
             ret = TERMKEY_RES_NONE;
 
+          if(ret == TERMKEY_RES_ERROR)
+            return ret;
           if(ret == TERMKEY_RES_NONE)
             return termkey_getkey_force(tk, key);
         }
@@ -877,8 +886,12 @@ TermKeyResult termkey_advisereadable(TermKey *tk)
   unsigned char buffer[64]; // Smaller than the default size
   ssize_t len = read(tk->fd, buffer, sizeof buffer);
 
-  if(len == -1 && (errno == EAGAIN || errno == EINTR))
+  if(len == -1) {
+    if(errno == EAGAIN)
       return TERMKEY_RES_NONE;
+    else
+      return TERMKEY_RES_ERROR;
+  }
   else if(len < 1) {
     tk->is_closed = 1;
     return TERMKEY_RES_NONE;

termkey.h.in

@@ -102,7 +102,8 @@ typedef enum {
   TERMKEY_RES_NONE,
   TERMKEY_RES_KEY,
   TERMKEY_RES_EOF,
-  TERMKEY_RES_AGAIN
+  TERMKEY_RES_AGAIN,
+  TERMKEY_RES_ERROR
 } TermKeyResult;
 
 typedef enum {

termkey_advisereadable.3

@@ -23,6 +23,9 @@ At least one byte was read.
 .TP
 .B TERMKEY_RES_NONE
 No nore bytes were read.
+.TP
+.B TERMKEY_RES_ERROR
+An IO error occured. \fIerrno\fP will be preserved.
 .SH "SEE ALSO"
 .BR termkey_new (3),
 .BR termkey_getkey (3),

termkey_waitkey.3.sh

@@ -25,6 +25,9 @@ A key event as been provided.
 .TP
 .B TERMKEY_RES_EOF
 No key events are ready and the terminal has been closed, so no more will arrive.
+.TP
+.B TERMKEY_RES_ERROR
+An IO error occured. \fIerrno\fP will be preserved.
 .SH EXAMPLE
 The following example program prints details of every keypress until the user presses "Ctrl-C".
 .PP