new function cinPeek(); named from c++ cin.peek()

CMakeLists.txt

@@ -4,15 +4,39 @@ project(getch C)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_COLOR_MAKEFILE ON)
 
-add_library(getch SHARED getch.c getch.h)
+add_library(libgetch SHARED getch.c getch.h)
+add_library(libgetch_static STATIC getch.c getch.h)
+
 add_executable(example example.c )
 add_executable(getchTest tests/test.c tests/getchTests.c)
-add_test(NAME getchTests
+
-        COMMAND getchTest
+add_test(NAME defaultTests
-        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+        COMMAND "getchTest"
-target_link_libraries(getchTest -L./build getch)
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-target_link_libraries(example -L./build getch)
+        )
+
+target_link_libraries(getchTest -L./build libgetch)
+target_link_libraries(example -L./build libgetch)
+
 if (ENABLE_TESTS EQUAL 1)
     enable_testing()
 endif ()
 
+add_custom_target(escapeTest getchTest escapeReturnsTest
+        COMMAND getchTest specialKeyTest
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+        USES_TERMINAL
+        )
+set_target_properties(libgetch PROPERTIES PUBLIC_HEADER getch.h)
+set_target_properties(libgetch PROPERTIES OUTPUT_NAME getch)
+set_target_properties(libgetch_static PROPERTIES OUTPUT_NAME getch_static)
+
+include(GNUInstallDirs)
+
+install(TARGETS libgetch libgetch_static
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        PUBLIC_HEADER
+        DESTINATION ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}
+        )
+

README.md

@@ -10,6 +10,8 @@ See https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/getch-getwc
 
 Difference is that _getch will read CTRL+C, or any control characters.
 
+There is also an extra function `int cinPeek()` that returns the next character in stdin without removing it.
+
 ### Note
 Make sure that the user calling the function is in the group "input"
 

example.c

@@ -11,4 +11,17 @@ int main() {
         key = _getch();
         printf("Special Key : %d\n", key);
     }
+
+   do {
+       key = _getch();
+       printf("Key : %d\n", key);
+   } while(key != 113);
+
+    _ungetch('A');
+
+    int res  = cinPeek();
+    int getch = _getch();
+
+    printf("%c : %c\n\r", res, getch);
+
 }

getch.c

@@ -14,13 +14,34 @@
 #include <glob.h>
 #include "getch.h"
 
-#define FKEY(k) ((k) >= KEY_F1 && (k) <= KEY_F10) || (k) == KEY_F12 || (k) == KEY_F11
-#define NOTNUMPAD(k) ((k) >= KEY_HOME && (k) <= KEY_DELETE)
-
 #define EVENT_DEVICE_GLOB "/dev/input/by-path/*-event-kbd"
 
+#define FKEY(k) ((k) >= KEY_F1 && (k) <= KEY_F10) || (k) == KEY_F12 || (k) == KEY_F11
+#define NOTNUMPAD(k) ((k) >= KEY_HOME && (k) <= KEY_DELETE)
+#define XOR_SWAP(a,b) do\
+    {\
+      (a) ^= (b);\
+      (b) ^= (a);\
+      (a) ^= (b);\
+    } while (0)
+
 static struct termios oldTermAttributes;
 
+inline static void reverseString(char * str)
+{
+    if (str)
+    {
+        char * end = str + strlen(str) - 1;
+
+        while (str < end)
+        {
+            XOR_SWAP(*str, *end);
+            str++;
+            end--;
+        }
+    }
+}
+
 static int discardRead(unsigned int length)
 {
     char buffer[length];
@@ -38,7 +59,7 @@ static int discardRead(unsigned int length)
     return (int)bytesRead;
 }
 
-static int getEventDevice(const char * device)
+static int getEventDevice(char ** device)
 {
     glob_t search;
 
@@ -64,7 +85,8 @@ static int getEventDevice(const char * device)
     for(int i = 0; i<search.gl_pathc;i++) {
         if(access(search.gl_pathv[i], F_OK) == 0) {
             pathLength = strlen(search.gl_pathv[i]) + 1;
-            strncpy((char *)device, search.gl_pathv[i], pathLength);
+            *device = (char *)malloc(pathLength);
+            strcpy(*device, search.gl_pathv[i]);
             globfree(&search);
             return 1;
         }
@@ -76,30 +98,33 @@ static int getEventDevice(const char * device)
 
 static unsigned short getScanCode()
 {
-    struct input_event inputEvent[3];
+    struct input_event inputEvent[5];
     int eventDevice;
 
-    const char device[FILENAME_MAX];
+    char *device;
-    if(getEventDevice(device) == -1) {
+    if(getEventDevice(&device) == -1) {
          perror("getEventDevice");
+         free(device);
         return KEY_RESERVED;
     }
 
     if( ( eventDevice = open(device, O_RDONLY)) == -1 ) {
+        free(device);
         perror("open");
         return KEY_RESERVED;
     };
 
-
+    free(device);
 
     if( read(eventDevice, &inputEvent, sizeof(inputEvent)) == -1) {
         close(eventDevice);
+        perror("read");
         return KEY_RESERVED;
     }
 
     close(eventDevice);
 
-    for(int i = 0;i<3;i++) {
+    for(int i = 0;i<5;i++) {
         if(inputEvent[i].type == EV_KEY && inputEvent[i].code != KEY_ENTER) {
             return inputEvent[i].code;
         }
@@ -153,7 +178,7 @@ static int readKey(void) {
 
         unsigned short scanCode = getScanCode();
 
-        if (scanCode == KEY_ESC || scanCode == KEY_RESERVED) {
+        if (scanCode == KEY_ESC ) {
             return 27;
         }
 
@@ -171,7 +196,6 @@ static int readKey(void) {
             case KEY_F2:
             case KEY_F3:
             case KEY_F4:
-
             case KEY_KP1: // END
             case KEY_KP2: // DOWN
             case KEY_KP4: // LEFT
@@ -199,6 +223,7 @@ static int readKey(void) {
 
             default:
                 discardBytes = 0;
+                break;
         }
 
         if (discardBytes != 0) {
@@ -225,7 +250,55 @@ int _getch(void) {
     return key;
 }
 
+int getch(void)
+{
+    return _getch();
+}
+
 int _ungetch(int ch)
 {
     return ungetc(ch, stdin);
+}
+
+int ungetch(int ch)
+{
+    return _ungetch(ch);
+}
+
+int *cinPeekCount(ushort count)
+{
+    char buffer[count];
+
+    int flags = fcntl(STDIN_FILENO, F_GETFL);
+
+    fcntl(STDIN_FILENO, F_SETFL, flags|O_NONBLOCK);
+
+    size_t byteCount = fread(&buffer, sizeof(char), count, stdin);
+
+    fcntl(STDIN_FILENO, F_SETFL, flags);
+
+    int *res = (int*)malloc(byteCount);
+
+    for(int i=0;i<byteCount;i++)
+    {
+            res[i] = (int)buffer[i];
+    }
+
+    reverseString(buffer);
+
+    for(int i=0;i<byteCount;i++) {
+        pushStdin(buffer[i]);
+    }
+
+    return res;
+}
+
+int cinPeek()
+{
+    int flags = fcntl(STDIN_FILENO, F_GETFL);
+    fcntl(STDIN_FILENO, F_SETFL, flags|O_NONBLOCK);
+    int result = fgetc(stdin);
+    fcntl(STDIN_FILENO, F_SETFL, flags);
+    ungetc(result, stdin);
+    return result;
 }

getch.h

@@ -8,6 +8,9 @@
 #define GETCH_H
 
 int _getch(void);
+int getch(void);
 int _ungetch(int ch);
+int ungetch(int ch);
+int cinPeek();
 
-#endif //GETCH_H
+#endif

tests/getchTests.c

@@ -5,15 +5,23 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h>
+#include <libevdev-1.0/libevdev/libevdev.h>
 #include <glob.h>
 
 #include "../getch.h"
+#define XOR_SWAP(a,b) do\
+    {\
+      (a) ^= (b);\
+      (b) ^= (a);\
+      (a) ^= (b);\
+    } while (0)
 
 #define EV_PRESSED 1
 #define EV_RELEASED 0
 
 inline static void writeToEventDevice(__u16 code)
 {
+    struct libevdev *dev = NULL;
     glob_t globResult;
     glob("/dev/input/by-path/*-event-kbd", GLOB_NOSORT, NULL, &globResult);
 
@@ -23,34 +31,45 @@ inline static void writeToEventDevice(__u16 code)
         exit(EXIT_FAILURE);
     }
 
-    char device[strlen(globResult.gl_pathv[0])];
+    char device[strlen(globResult.gl_pathv[0])+1];
-    strncpy(device, globResult.gl_pathv[0], strlen(globResult.gl_pathv[0]) + 1);
+    strcpy(device, globResult.gl_pathv[0]);
     globfree(&globResult);
 
-    struct input_event inputEvent[2];
+    struct input_event inputEvent[3];
-    int eventDevice = open(device, O_WRONLY);
+    int eventDevice = open(device, O_WRONLY|O_NONBLOCK);
 
     if(eventDevice == -1) {
         perror("open");
         exit(EXIT_FAILURE);
     }
 
-    for(int i=0; i<2;i++) {
+    inputEvent[0].time.tv_usec = 0;
-        gettimeofday(&inputEvent[i].time, NULL);
+    inputEvent[0].time.tv_sec = 0;
-        inputEvent[i].type = EV_KEY;
+    inputEvent[0].type = 4;
-        inputEvent[i].code = code;
+    inputEvent[0].code = 4;
-        inputEvent[i].value = i ? EV_RELEASED : EV_PRESSED;
+    inputEvent[0].value = code;
+
+    inputEvent[1].time.tv_usec = 0;
+    inputEvent[1].time.tv_sec = 0;
+    inputEvent[1].type = EV_KEY;
+    inputEvent[1].code = code;
+    inputEvent[1].value = EV_PRESSED;
+
+    inputEvent[2].time.tv_usec = 0;
+    inputEvent[2].time.tv_sec = 0;
+    inputEvent[2].type = EV_KEY;
+    inputEvent[2].code = code;
+    inputEvent[2].value = EV_RELEASED;
+
+
+    int res;
+
+    res = write(eventDevice, &inputEvent, sizeof(inputEvent));
+    if(res == -1) {
+        perror("Write");
     }
 
-    write(eventDevice, &inputEvent, sizeof(inputEvent));
+   close(eventDevice);
-
-
-    close(eventDevice);
-
-    sync();
-
-    fflush(NULL);
-
 }
 
 inline static void reverseString(char * str)
@@ -59,24 +78,12 @@ inline static void reverseString(char * str)
     {
         char * end = str + strlen(str) - 1;
 
-        // swap the values in the two given variables
-        // XXX: fails when a and b refer to same memory location
-#   define XOR_SWAP(a,b) do\
-    {\
-      (a) ^= (b);\
-      (b) ^= (a);\
-      (a) ^= (b);\
-    } while (0)
-
-        // walk inwards from both ends of the string,
-        // swapping until we get to the middle
         while (str < end)
         {
             XOR_SWAP(*str, *end);
             str++;
             end--;
         }
-#   undef XOR_SWAP
     }
 }
 
@@ -94,12 +101,12 @@ inline static void writeStringToStdin(char * string)
 }
 
 static char *asciiCodes[3] = {
-        "\x1bOPP",
+        "\x1bOP",
         "\x1b[H",
-        "\x1bOJ"
+        "\x1bOQ"
 };
 
-static int scanCodes[3] = { KEY_F1, KEY_HOME, KEY_F5 };
+static int scanCodes[3] = { KEY_F1, KEY_HOME, KEY_F2 };
 
 CTEST(getchTests, simpleGetchSetReturn_q)
 {
@@ -113,9 +120,8 @@ CTEST(getchTests, simpleGetchSetReturn_q)
 
 CTEST(getchTests, SpecialKey)
 {
-
-    writeStringToStdin(asciiCodes[0]);
     writeToEventDevice(scanCodes[0]);
+    writeStringToStdin(asciiCodes[0]);
 
     int key = _getch();
     int code = _getch();
@@ -126,10 +132,8 @@ CTEST(getchTests, SpecialKey)
 
 CTEST(specialKeyTests, Home)
 {
-
+    writeToEventDevice(scanCodes[1]);
     writeStringToStdin(asciiCodes[1]);
-    writeToEventDevice(KEY_HOME);
-
     int key = _getch();
     int code = _getch();
 
@@ -139,8 +143,10 @@ CTEST(specialKeyTests, Home)
 
 CTEST(escapeReturnsTest, Esc)
 {
-    ungetc(27, stdin);
     writeToEventDevice(KEY_ESC);
+    ungetc(27, stdin);
+
+
     int key = _getch();
 
     ASSERT_EQUAL(27, key);