ls(1) now pipe(2) into column(1) if stdout(3) isatty(2).

This saves precious screen space as Sortix only supports 25-line ttys.

utils/ls.cpp

@@ -5,6 +5,9 @@
 #include <errno.h>
 #include <error.h>
 #include <dirent.h>
+#include <sys/wait.h>
+#include <libmaxsi/platform.h>
+#include <libmaxsi/process.h>
 
 int ls(const char* path)
 {
@@ -32,6 +35,33 @@ int ls(const char* path)
 
 int main(int argc, char* argv[])
 {
+	pid_t childpid = 0;
+	if ( isatty(1) )
+	{
+		int pipes[2];
+		if ( pipe(pipes) ) { perror("pipe"); return 1; }
+		childpid = fork();
+		if ( childpid < 0 ) { perror("fork"); return 1; }
+		if ( childpid )
+		{
+			close(1);
+			dup(pipes[1]);
+			close(pipes[0]);
+			close(pipes[1]);
+		}
+		else
+		{
+			close(0);
+			dup(pipes[0]);
+			close(pipes[0]);
+			close(pipes[1]);
+			const char* columner = "column";
+			const char* argv[] = { columner };
+			Maxsi::Process::Execute(columner, 1, argv);
+			error(127, errno, "%s", columner);
+		}
+	}
+
 	const size_t CWD_SIZE = 512;
 	char cwd[CWD_SIZE];
 	const char* path = getcwd(cwd, CWD_SIZE);
@@ -39,5 +69,10 @@ int main(int argc, char* argv[])
 
 	if ( 1 < argc ) { path = argv[1]; }
 
-	return ls(path);
+	int result = ls(path);
+
+	int status;
+	if ( childpid ) { close(1); wait(&status); }
+	return result;
 }
+