Add a simple /bin/more.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/36bd53b36a7

Kernel/sync.sh

@@ -29,6 +29,7 @@ cp -v ../Userland/tty mnt/bin/tty
 cp -v ../Userland/mkdir mnt/bin/mkdir
 cp -v ../Userland/touch mnt/bin/touch
 cp -v ../Userland/sync mnt/bin/sync
+cp -v ../Userland/more mnt/bin/more
 sh sync-local.sh
 cp -v kernel.map mnt/
 ln -s dir_a mnt/dir_cur

Userland/.gitignore

@@ -20,3 +20,4 @@ fgrep
 mkdir
 touch
 sync
+more

Userland/Makefile

@@ -17,7 +17,8 @@ OBJS = \
        fgrep.o \
        tty.o \
        mkdir.o \
-       touch.o
+       touch.o \
+       more.o
 
 APPS = \
        id \
@@ -39,7 +40,8 @@ APPS = \
        tty \
        mkdir \
        touch \
-       sync
+       sync \
+       more
 
 ARCH_FLAGS =
 STANDARD_FLAGS = -std=c++17 -nostdinc++ -nostdlib -nostdinc
@@ -119,6 +121,9 @@ touch: touch.o
 sync: sync.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 
+more: more.o
+	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
+
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 

Userland/more.cpp

@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+static int key_fd;
+
+void wait_for_key()
+{
+    printf("\033[7m--[ more ]--\033[0m");
+    fflush(stdout);
+    char dummy;
+    read(key_fd, &dummy, 1);
+    printf("\n");
+}
+
+int main(int argc, char** argv)
+{
+    (void) argc;
+    (void) argv;
+
+    key_fd = open(ttyname(1), O_RDONLY);
+    if (key_fd < 0) {
+        perror("open");
+        return 1;
+    }
+
+    struct winsize ws;
+    ioctl(1, TIOCGWINSZ, &ws);
+
+    unsigned lines_printed = 0;
+    while (!feof(stdin)) {
+        char buffer[BUFSIZ];
+        auto* str = fgets(buffer, sizeof(buffer), stdin);
+        if (!str)
+            break;
+        printf(str);
+        ++lines_printed;
+        if ((lines_printed % (ws.ws_row - 1)) == 0) { 
+            wait_for_key();
+        }
+
+    }
+
+    close(key_fd);
+    return 0;
+}