libc: Add close() and stdio functions

Signed-off-by: Kaimakan71 <undefined.foss@gmail.com>
Signed-off-by: Ian Moffett <ian@osmora.org>

21 files changed, 654 insertions, 10 deletions

diff --git a/lib/libc/Makefile b/lib/libc/Makefile
index 2314edc..bc15b0f 100644
--- a/lib/libc/Makefile
+++ b/lib/libc/Makefile
@@ -29,4 +29,5 @@ build/:
 
 .PHONY: clean
 clean:
+	rm -f $(LIBC_OBJ) $(LIBC_ASMOBJ)
 	rm -rf build/
diff --git a/lib/libc/include/stdio.h b/lib/libc/include/stdio.h
new file mode 100644
index 0000000..b19230c
--- /dev/null
+++ b/lib/libc/include/stdio.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _STDIO_H
+#define _STDIO_H
+
+#include <stddef.h>
+
+#define EOF (int)-1
+
+#define FILE_READ  (1 << 0)
+#define FILE_WRITE (1 << 1)
+
+typedef struct {
+    int fd;
+    int flags;
+
+    char *write_buf;
+    char *write_pos;
+    char *write_end;
+} FILE;
+
+extern FILE *stdout;
+
+FILE *fopen(const char *pathname, const char *mode);
+FILE *fdopen(int fd, const char *mode);
+
+size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
+size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream);
+
+int fputc(int c, FILE *stream);
+#define putc fputc
+int putchar(int c);
+
+int fputs(const char *s, FILE *stream);
+int puts(const char *s);
+
+int fflush(FILE *stream);
+int fclose(FILE *stream);
+
+#endif  /* !_STDIO_H */
diff --git a/lib/libc/include/string.h b/lib/libc/include/string.h
index 1b270c7..a49dcba 100644
--- a/lib/libc/include/string.h
+++ b/lib/libc/include/string.h
@@ -31,7 +31,6 @@
 #define _STRING_H
 
 #include <stddef.h>
-#include <stdint.h>
 
 void *memcpy(void *dest, const void *src, size_t n);
 void *memccpy(void *dest, const void *src, int c, size_t n);
@@ -40,7 +39,7 @@ void *memset(void *s, int c, size_t n);
 int memcmp(const void *s1, const void *s2, size_t n);
 void *memchr(const void *s, int c, size_t n);
 
-size_t strlen(const char  *s);
+size_t strlen(const char *s);
 int strcmp(const char *s1, const char *s2);
 int strncmp(const char *s1, const char *s2, size_t n);
 
diff --git a/lib/libc/include/unistd.h b/lib/libc/include/unistd.h
index 8d92422..f82c83a 100644
--- a/lib/libc/include/unistd.h
+++ b/lib/libc/include/unistd.h
@@ -42,6 +42,7 @@ extern "C" {
 _Noreturn void _exit(int status);
 ssize_t write(int fd, const void *buf, size_t count);
 ssize_t read(int fd, void *buf, size_t count);
+int close(int fd);
 
 #if defined(__cplusplus)
 }
diff --git a/lib/libc/src/main.c b/lib/libc/src/main.c
index 477842b..890f3c8 100644
--- a/lib/libc/src/main.c
+++ b/lib/libc/src/main.c
@@ -28,9 +28,13 @@
  */
 
 #include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
 
 int main(int argc, const char **argv, const char **envp);
 
+FILE *stdout;
+
 int
 __libc_entry(uint64_t *ctx)
 {
@@ -38,5 +42,7 @@ __libc_entry(uint64_t *ctx)
     const char **argv = (const char **)(ctx + 1);
     const char **envp = (const char **)(argv + argc + 1);
 
+    stdout = fdopen(STDOUT_FILENO, "a");
+
     return main(argc, argv, envp);
 }
diff --git a/lib/libc/src/stdio/fclose.c b/lib/libc/src/stdio/fclose.c
new file mode 100644
index 0000000..f2a48bb
--- /dev/null
+++ b/lib/libc/src/stdio/fclose.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+int
+fclose(FILE *stream)
+{
+    if (stream == NULL)
+        return EOF;
+
+    if (close(stream->fd) != 0)
+        return EOF;
+
+    return 0;
+}
diff --git a/lib/libc/src/stdio/fdopen.c b/lib/libc/src/stdio/fdopen.c
new file mode 100644
index 0000000..37352e9
--- /dev/null
+++ b/lib/libc/src/stdio/fdopen.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+
+#include <unistd.h>
+
+#define WRITE_BUF_SIZE 128
+
+/* TODO: Allocate these once malloc() is implemented */
+static FILE default_stream;
+static char default_write_buf[WRITE_BUF_SIZE];
+
+FILE*
+fdopen(int fd, const char *mode)
+{
+    FILE *stream;
+    int flags;
+
+    if (mode == NULL)
+        return NULL;
+
+    /* Determine stream flags */
+    flags = 0;
+    switch (mode[0]) {
+    case 'r':
+        flags |= FILE_READ;
+        if (mode[1] == '+') {
+            flags |= FILE_WRITE;
+        }
+        break;
+    case 'w':
+    case 'a':
+        flags |= FILE_WRITE;
+        if (mode[1] == '+') {
+            flags |= FILE_READ;
+        }
+        break;
+    default:
+        return NULL;
+    }
+
+    /* Create stream */
+    stream = &default_stream;
+    stream->fd = fd;
+    stream->flags = flags;
+
+    /* Create write buffer if needed */
+    if (flags & FILE_WRITE) {
+        stream->write_buf = default_write_buf;
+        stream->write_pos = stream->write_buf;
+        stream->write_end = stream->write_buf + WRITE_BUF_SIZE;
+    }
+
+    return stream;
+}
diff --git a/lib/libc/src/stdio/fflush.c b/lib/libc/src/stdio/fflush.c
new file mode 100644
index 0000000..0d6a41e
--- /dev/null
+++ b/lib/libc/src/stdio/fflush.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+int
+fflush(FILE *stream)
+{
+    size_t size;
+
+    if (stream == NULL || !(stream->flags & FILE_WRITE))
+        return EOF;
+
+    /* Check if write buffer is empty */
+    if (stream->write_pos == stream->write_buf)
+        return 0;
+
+    /* Write buffer to file */
+    size = stream->write_pos - stream->write_buf;
+    if ((size_t)write(stream->fd, stream->write_buf, size) != size)
+        return EOF;
+
+    stream->write_pos = stream->write_buf;
+    return 0;
+}
diff --git a/lib/libc/src/stdio/fopen.c b/lib/libc/src/stdio/fopen.c
new file mode 100644
index 0000000..3d1153b
--- /dev/null
+++ b/lib/libc/src/stdio/fopen.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+FILE*
+fopen(const char *pathname, const char *mode)
+{
+    int open_flags;
+    int fd;
+
+    if (mode == NULL)
+        return NULL;
+
+    /* Determine open flags */
+    switch (mode[0]) {
+    case 'r':
+        if (mode[1] == '+') {
+            open_flags = O_RDWR;
+        } else {
+            open_flags = O_RDONLY;
+        }
+        break;
+    case 'w':
+    case 'a':
+    /* TODO: Change this once O_CREAT, O_TRUNC, and O_APPEND are added */
+        if (mode[1] == '+') {
+            open_flags = O_RDWR;
+        } else {
+            open_flags = O_WRONLY;
+        }
+        break;
+    default:
+        return NULL;
+    }
+
+    /* Try to open file */
+    fd = open(pathname, open_flags);
+    if (fd == -1)
+        return NULL;
+
+    /* Create stream with fdopen */
+    return fdopen(fd, mode);
+}
diff --git a/lib/libc/src/stdio/fputc.c b/lib/libc/src/stdio/fputc.c
new file mode 100644
index 0000000..c240426
--- /dev/null
+++ b/lib/libc/src/stdio/fputc.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+
+int
+fputc(int c, FILE *stream)
+{
+    unsigned char ch;
+
+    if (stream == NULL || !(stream->flags & FILE_WRITE))
+        return EOF;
+
+    /* Try to flush stream if needed */
+    ch = (unsigned char)c;
+    if ((stream->write_end - stream->write_pos) < 1) {
+        if (fflush(stream) == EOF)
+            return EOF;
+    }
+    *stream->write_pos++ = ch;
+
+    return (int)ch;
+}
diff --git a/lib/libc/src/stdio/fputs.c b/lib/libc/src/stdio/fputs.c
new file mode 100644
index 0000000..e8335e9
--- /dev/null
+++ b/lib/libc/src/stdio/fputs.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+int
+fputs(const char *s, FILE *stream)
+{
+    size_t len;
+
+    if (s == NULL)
+        return EOF;
+
+    len = strlen(s);
+    if (fwrite(s, 1, len, stream) != len)
+        return EOF;
+
+    return 0;
+}
diff --git a/lib/libc/src/stdio/fread.c b/lib/libc/src/stdio/fread.c
new file mode 100644
index 0000000..9fe5bd0
--- /dev/null
+++ b/lib/libc/src/stdio/fread.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+size_t
+fread(void *ptr, size_t size, size_t nmemb, FILE *stream)
+{
+    if (stream == NULL || !(stream->flags & FILE_READ))
+        return 0;
+
+    return (size_t)read(stream->fd, ptr, size * nmemb) / size;
+}
diff --git a/lib/libc/src/stdio/fwrite.c b/lib/libc/src/stdio/fwrite.c
new file mode 100644
index 0000000..ea79009
--- /dev/null
+++ b/lib/libc/src/stdio/fwrite.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+size_t
+fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
+{
+    const char *pos;
+    size_t n_remaining;
+
+    if (ptr == NULL || stream == NULL)
+        return 0;
+    if (size == 0 || nmemb == 0)
+        return 0;
+    if (!(stream->flags & FILE_WRITE))
+        return 0;
+
+    /* Write data to buffer, flushing as needed */
+    pos = ptr;
+    n_remaining = size * nmemb;
+    while (n_remaining > 0) {
+        size_t n_free = stream->write_end - stream->write_pos;
+
+        /* If enough buffer space is available, finish writing */
+        if (n_remaining < n_free) {
+            memcpy(stream->write_pos, pos, n_remaining);
+            stream->write_pos += n_remaining;
+            break;
+        }
+
+        /* Otherwise, write as much as possible now */
+        memcpy(stream->write_pos, pos, n_free);
+        stream->write_pos += n_free;
+
+        /* Return if flushing fails */
+        if (fflush(stream) == EOF)
+            return nmemb - (n_remaining / size);
+
+        pos += n_free;
+        n_remaining -= n_free;
+    }
+
+    return nmemb;
+}
diff --git a/lib/libc/src/stdio/putchar.c b/lib/libc/src/stdio/putchar.c
new file mode 100644
index 0000000..dfb34be
--- /dev/null
+++ b/lib/libc/src/stdio/putchar.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+
+int
+putchar(int c)
+{
+    return fputc(c, stdout);
+}
diff --git a/lib/libc/src/stdio/puts.c b/lib/libc/src/stdio/puts.c
new file mode 100644
index 0000000..c1b027d
--- /dev/null
+++ b/lib/libc/src/stdio/puts.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+
+int
+puts(const char *s)
+{
+    if (fputs(s, stdout) == EOF)
+        return EOF;
+
+    if (putchar('\n') == EOF)
+        return EOF;
+
+    return 0;
+}
diff --git a/lib/libc/src/string/memcpy.c b/lib/libc/src/string/memcpy.c
index 9851e07..efbf1bb 100644
--- a/lib/libc/src/string/memcpy.c
+++ b/lib/libc/src/string/memcpy.c
@@ -32,9 +32,8 @@
 void *
 memcpy(void *dest, const void *src, size_t n)
 {
-    for (size_t i = 0; i < n; i++) {
+    for (size_t i = 0; i < n; i++)
         ((char *)dest)[i] = ((char *)src)[i];
-    }
 
     return dest;
 }
diff --git a/lib/libc/src/string/memmove.c b/lib/libc/src/string/memmove.c
index bbf9a0d..d8a94f7 100644
--- a/lib/libc/src/string/memmove.c
+++ b/lib/libc/src/string/memmove.c
@@ -27,6 +27,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <stdint.h>
 #include <string.h>
 
 void *
diff --git a/lib/libc/src/string/memset.c b/lib/libc/src/string/memset.c
index 928441a..ecceffa 100644
--- a/lib/libc/src/string/memset.c
+++ b/lib/libc/src/string/memset.c
@@ -32,9 +32,8 @@
 void *
 memset(void *s, int c, size_t n)
 {
-    for (size_t i = 0; i < n; i++) {
+    for (size_t i = 0; i < n; i++)
         ((char *)s)[i] = (char)c;
-    }
 
     return s;
 }
diff --git a/lib/libc/src/string/strcmp.c b/lib/libc/src/string/strcmp.c
index 9d9c5f1..b9e941a 100644
--- a/lib/libc/src/string/strcmp.c
+++ b/lib/libc/src/string/strcmp.c
@@ -32,8 +32,8 @@
 int
 strcmp(const char *s1, const char *s2)
 {
-    char *p1 = (char*)s1;
-    char *p2 = (char*)s2;
+    char *p1 = (char *)s1;
+    char *p2 = (char *)s2;
 
     while (*p1 || *p2) {
         if (*p1 < *p2)
diff --git a/lib/libc/src/string/strncmp.c b/lib/libc/src/string/strncmp.c
index 47d562a..7f4df75 100644
--- a/lib/libc/src/string/strncmp.c
+++ b/lib/libc/src/string/strncmp.c
@@ -32,8 +32,8 @@
 int
 strncmp(const char *s1, const char *s2, size_t n)
 {
-    char *p1 = (char*)s1;
-    char *p2 = (char*)s2;
+    char *p1 = (char *)s1;
+    char *p2 = (char *)s2;
 
     for (size_t i = 0; i < n; i++) {
         if (!*p1 && !*p2)
diff --git a/lib/libc/src/unistd/close.c b/lib/libc/src/unistd/close.c
new file mode 100644
index 0000000..3f1ca0f
--- /dev/null
+++ b/lib/libc/src/unistd/close.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/syscall.h>
+
+int
+close(int fd)
+{
+    return syscall(SYS_close, fd);
+}