Added a simple pager program while we wait for less(1) to be ported.

utils/Makefile

@@ -21,6 +21,7 @@ uname \
 idle \
 editor \
 kill \
+pager \
 
 BINARIES:=$(addprefix $(INITRDDIR)/,$(LOCALBINARIES))
 

utils/pager.cpp

@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <error.h>
+#include <libmaxsi/platform.h>
+#include <libmaxsi/sortix-keyboard.h>
+
+using namespace Maxsi;
+
+int main(int argc, char* argv[])
+{
+	if ( argc < 2 ) { printf("usage: %s [FILE] ...\n", argv[0]); return 0; }
+	const int HEIGHT = 25;
+	const int WIDTH = 80;
+	int linesleft = HEIGHT-1;
+	int result = 0;
+	size_t charleft = WIDTH;
+	for ( int i = 1; i < argc; i++ )
+	{
+		int fd = ( strcmp(argv[i], "-") == 0 ) ? 0 : open(argv[i], O_RDONLY);
+		if ( fd < 0 ) { result = 1; perror(argv[i]); continue; }
+		const size_t BUFFER_SIZE = 4096;
+		char buffer[BUFFER_SIZE];
+		while ( true )
+		{
+			ssize_t numbytes = read(fd, buffer, BUFFER_SIZE);
+			if ( !numbytes ) { break; }
+			if ( numbytes < 0 )
+			{
+				result = 1;
+				error(0, errno, "read: %s", argv[i]);
+				break;
+			}
+			for ( ssize_t i = 0; i < numbytes; i++ )
+			{
+				bool printed = false;
+				char c = buffer[i];
+				if ( c == '\n' ) { charleft = WIDTH; }
+				bool eol = (c == '\n') || !charleft;
+				if ( eol ) { charleft = WIDTH; }
+				if ( eol && !linesleft )
+				{
+					printf("\n--pager--");
+					fflush(stdout);
+					uint32_t codepoint;
+					bool doexit = false;
+					do
+					{
+						unsigned method = System::Keyboard::POLL;
+						codepoint = System::Keyboard::ReceiveKeystroke(method);
+						if ( codepoint == Keyboard::DOWN ) { break; }
+						if ( codepoint == Keyboard::PGDOWN ) { linesleft = HEIGHT-1; break; }
+						if ( codepoint == 'q' ) { doexit = true; break; }
+					}
+					while ( codepoint != '\n' );
+					printf("\r\e[J");
+					if ( doexit ) { exit(result); }
+					continue;
+				}
+				if ( eol && linesleft ) { linesleft--; }
+				printf("%c", c);
+				charleft--;
+				if ( c == '\t' ) { charleft &= ~(4-1); }
+			}
+		}
+		if ( fd != 0 ) { close(fd); }
+	}
+	return result;
+}