liblinux++

commit 3422713679c8528a5feedb1b170c1a55adb1ab0f
parent dc63fe778af6488f6b12a78b6b41a4beaaa07663
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Tue, 23 Dec 2025 15:30:54 +0000

convert paste to .cpp and handle pointer syscall results

Diffstat:
M
linux.hpp
 | 
5
++++-
D
paste.c
 | 
57
---------------------------------------------------------
A
paste.cpp
 | 
60
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 64 insertions(+), 58 deletions(-)
diff --git a/linux.hpp b/linux.hpp
@@ -89,7 +89,10 @@ struct syscall_result
 	{
 		if (!*this)
 			__builtin_trap();
-		return static_cast<T>(val);
+		if constexpr (__is_pointer(T))
+			return reinterpret_cast<T>(val);
+		else
+			return static_cast<T>(val);
 	}
 	errno_t err() const
 	{
diff --git a/paste.c b/paste.c
@@ -1,57 +0,0 @@
-#include "linux.h"
-
-struct input
-{
-	int fd;
-	unsigned short start, end;
-	char buf[0x1000 - 8];
-};
-
-extern struct input mappable[];
-static int n_inputs;
-static char getc(struct input* in)
-{
-	if (in->start == in->end)
-	{
-		in->start = 0;
-		in->end = 0;
-		int n = read(in->fd, in->buf, 0x1000-8);
-		if (n <= 0)
-			return 0;
-		in->end = n;
-	}
-	return in->buf[in->start++];
-}
-
-int main(int argc, char* argv[])
-{
-	for (int i = 1; i < argc; ++i)
-	{
-		int fd = openat(AT_FDCWD, argv[i], 0, 0);
-		if (get_errno(fd))
-			return 1;
-		intptr_t m = mmap(mappable + n_inputs++, sizeof(struct input), PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-		if (get_errno(m))
-			return 2;
-		((struct input*)m)->fd = fd;
-	}
-
-	for (;;)
-	{
-		for (int i = 0; i < n_inputs; ++i)
-		{
-			struct input* in = mappable + i;
-
-			for (;;)
-			{
-				char c = getc(in);
-				if (!c)
-					return 0;
-				if (c == '\n')
-					break;
-				write(1, &c, 1);
-			}
-			write(1, i + 1 == n_inputs ? "\n" : "\t", 1);
-		}
-	}
-}
diff --git a/paste.cpp b/paste.cpp
@@ -0,0 +1,60 @@
+#include "linux.hpp"
+
+struct input
+{
+	file fd;
+	unsigned short start, end;
+	char buf[0x1000 - 8];
+};
+
+extern struct input mappable[];
+static int n_inputs;
+static char getc(struct input* in)
+{
+	if (in->start == in->end)
+	{
+		in->start = 0;
+		in->end = 0;
+		auto res = read(in->fd, in->buf, 0x1000-8);
+		if (!res)
+			exit(1);
+		auto n = *res;
+		if (n <= 0)
+			return 0;
+		in->end = n;
+	}
+	return in->buf[in->start++];
+}
+
+int main(int argc, char* argv[])
+{
+	for (int i = 1; i < argc; ++i)
+	{
+		auto fd = openat(AT_FDCWD, argv[i], 0, 0);
+		if (!fd)
+			return 1;
+		auto m = mmap(mappable + n_inputs++, sizeof(struct input), PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, {}, 0);
+		if (!m)
+			return 2;
+		static_cast<input*>(*m)->fd = *fd;
+	}
+
+	for (;;)
+	{
+		for (int i = 0; i < n_inputs; ++i)
+		{
+			input* in = mappable + i;
+
+			for (;;)
+			{
+				char c = getc(in);
+				if (!c)
+					return 0;
+				if (c == '\n')
+					break;
+				write(stdout, &c, 1);
+			}
+			write(stdout, i + 1 == n_inputs ? "\n" : "\t", 1);
+		}
+	}
+}