21 files changed, 413 insertions, 43 deletions

diff --git a/src/libc/include/fcntl.h b/src/libc/include/fcntl.h
index 282ced8..1edf2fc 100644
--- a/src/libc/include/fcntl.h
+++ b/src/libc/include/fcntl.h
@@ -19,11 +19,12 @@
 #ifndef _FCNTL_H
 #define _FCNTL_H
 
-enum
-{
-    O_RDONLY = 1,
-    O_WRONLY = 1 << 1,
-    O_RDWR = O_RDONLY | O_WRONLY
-};
+#define O_RDONLY 1
+#define O_WRONLY (1 << 1)
+#define O_CREAT (1 << 2)
+#define O_APPEND (1 << 3)
+#define O_RDWR (O_RDONLY | O_WRONLY)
+
+int open(const char *__path, int __flags, ...);
 
 #endif
diff --git a/src/libc/include/stdio.h b/src/libc/include/stdio.h
index b9c1a38..efa60dd 100644
--- a/src/libc/include/stdio.h
+++ b/src/libc/include/stdio.h
@@ -19,8 +19,23 @@
 #ifndef _STDIO_H
 #define _STDIO_H
 
-enum {EOF = -1};
+#include <stddef.h>
 
+#define BUFSIZ 128
+#define FOPEN_MAX 8
+#define FILENAME_MAX 128
+#define EOF -1
+#define stdin __stdin
+#define stdout __stdout
+#define stderr __stderr
+
+typedef struct __file FILE;
+extern FILE *__stdin, *__stdout, *__stderr;
+
+int fputc(int __c, FILE *__f);
+FILE *fopen(const char *__path, const char *__mode);
+size_t fwrite(const void *__p, size_t __sz, size_t __nmemb, FILE *__f);
+int putc(int __c, FILE *__f);
 int puts(const char *__s);
 int putchar(int __c);
 
diff --git a/src/libc/include/stdlib.h b/src/libc/include/stdlib.h
index 2704fca..b6e092e 100644
--- a/src/libc/include/stdlib.h
+++ b/src/libc/include/stdlib.h
@@ -57,10 +57,10 @@ div_t div(int __numerator, int __denominator);
 #define RESET "\x1b[0m"
 
 #define malloc(__n) ({void *__p; \
+    int Printf(const char *, ...); \
     Printf(GREEN "-> %s:%d (%s)", __FILE__, __LINE__, __func__); \
     __p = __malloc(__n); \
     Printf(", p=%p" RESET "\n", __p); \
-    int Printf(const char *, ...); \
     size_t ta_num_free(); \
     size_t ta_num_used(); \
     size_t ta_num_fresh(); \
@@ -71,13 +71,13 @@ div_t div(int __numerator, int __denominator);
     __p;})
 
 #define realloc(__p, __n) ({void *__np; \
+    int Printf(const char *, ...); \
+    size_t ta_num_free(); \
+    size_t ta_num_used(); \
+    size_t ta_num_fresh(); \
     Printf(YELLOW "-> %s:%d (%s)", __FILE__, __LINE__, __func__); \
     __np = __realloc(__p, __n); \
     Printf(", np=%p" RESET "\n", __np); \
-    int Printf(const char *, ...); \
-    size_t ta_num_free(); \
-size_t ta_num_used(); \
-size_t ta_num_fresh(); \
     Printf("%s: free=%lu, used=%lu, fresh=%lu\n", __func__, \
         (unsigned long)ta_num_free(), \
         (unsigned long)ta_num_used(), \
@@ -85,13 +85,13 @@ size_t ta_num_fresh(); \
     __np;})
 
 #define calloc(__n, __sz) ({void *__p; \
+    int Printf(const char *, ...); \
+    size_t ta_num_free(); \
+    size_t ta_num_used(); \
+    size_t ta_num_fresh(); \
     Printf(YELLOW "-> %s:%d (%s)", __FILE__, __LINE__, __func__); \
     __p = __calloc(__n, __sz); \
     Printf(", p=%p" RESET "\n", __p); \
-    int Printf(const char *, ...); \
-    size_t ta_num_free(); \
-size_t ta_num_used(); \
-size_t ta_num_fresh(); \
     Printf("%s: free=%lu, used=%lu, fresh=%lu\n", __func__, \
         (unsigned long)ta_num_free(), \
         (unsigned long)ta_num_used(), \
@@ -100,18 +100,18 @@ size_t ta_num_fresh(); \
 
 #define free(__p) ({ \
     int Printf(const char *, ...); \
+    size_t ta_num_free(); \
+    size_t ta_num_used(); \
+    size_t ta_num_fresh(); \
     Printf(RED "<- %s:%d (%s), p=%p" RESET "\n", \
         __FILE__, __LINE__, __func__, __p); \
-        size_t ta_num_free(); \
-        size_t ta_num_used(); \
-        size_t ta_num_fresh(); \
-        __free(__p);\
-        Printf("%s: free=%lu, used=%lu, fresh=%lu\n", \
-            __func__, \
-            (unsigned long)ta_num_free(), \
-            (unsigned long)ta_num_used(), \
-            (unsigned long)ta_num_fresh()); \
-        })
+    __free(__p);\
+    Printf("%s: free=%lu, used=%lu, fresh=%lu\n", \
+        __func__, \
+        (unsigned long)ta_num_free(), \
+        (unsigned long)ta_num_used(), \
+        (unsigned long)ta_num_fresh()); \
+    })
 #endif
 
 #endif
diff --git a/src/libc/include/sys/stat.h b/src/libc/include/sys/stat.h
index 08fcf9a..b5ef13d 100644
--- a/src/libc/include/sys/stat.h
+++ b/src/libc/include/sys/stat.h
@@ -22,6 +22,35 @@
 #include <sys/types.h>
 #include <time.h>
 
+#define S_IRWXU 0700
+#define S_IRUSR 0400
+#define S_IWUSR 0200
+#define S_IXUSR 0100
+#define S_IRWXG 070
+#define S_IRGRP 040
+#define S_IWGRP 020
+#define S_IXGRP 010
+#define S_IRWXO 07
+#define S_IROTH 04
+#define S_IWOTH 02
+#define S_IXOTH 1
+
+#define S_IFBLK ((mode_t)1)
+#define S_IFCHR ((mode_t)(1 << 1))
+#define S_IFIFO ((mode_t)(1 << 2))
+#define S_IFREG ((mode_t)(1 << 3))
+#define S_IFDIR ((mode_t)(1 << 4))
+#define S_IFLNK ((mode_t)(1 << 5))
+#define S_IFSOCK ((mode_t)(1 << 6))
+
+#define S_ISBLK(__m) ((__m) & S_IFBLK)
+#define S_ISCHR(__m) ((__m) & S_IFCHR)
+#define S_ISDIR(__m) ((__m) & S_IFDIR)
+#define S_ISFIFO(__m) ((__m) & S_IFIFO)
+#define S_ISREG(__m) ((__m) & S_IFREG)
+#define S_ISLNK(__m) ((__m) & S_IFLNK)
+#define S_ISSOCK(__m) ((__m) & S_IFSOCK)
+
 struct stat
 {
     dev_t st_dev;
@@ -37,6 +66,7 @@ struct stat
     blkcnt_t st_blocks;
 };
 
-int mkdir(const char *pathname, mode_t flags);
+int mkdir(const char *__pathname, mode_t __flags);
+mode_t umask(mode_t __mask);
 
 #endif
diff --git a/src/libc/include/sys/types.h b/src/libc/include/sys/types.h
index 86ca604..fc231f1 100644
--- a/src/libc/include/sys/types.h
+++ b/src/libc/include/sys/types.h
@@ -22,5 +22,6 @@
 typedef unsigned dev_t, mode_t, nlink_t, uid_t, gid_t, blksize_t, blkcnt_t;
 typedef unsigned long ino_t, off_t;
 typedef int pid_t;
+typedef long ssize_t;
 
 #endif
diff --git a/src/libc/include/unistd.h b/src/libc/include/unistd.h
index ec4fc13..dcf0336 100644
--- a/src/libc/include/unistd.h
+++ b/src/libc/include/unistd.h
@@ -19,8 +19,20 @@
 #ifndef _UNISTD_H
 #define _UNISTD_H
 
+#include <stddef.h>
 #include <stdint.h>
+#include <sys/types.h>
 
-void *sbrk(intptr_t increment);
+enum
+{
+    STDIN_FILENO,
+    STDOUT_FILENO,
+    STDERR_FILENO
+};
+
+void *sbrk(intptr_t __increment);
+ssize_t read(int __fd, void *__buf, size_t __n);
+ssize_t write(int __fd, const void *__buf, size_t __n);
+int close(int __fd);
 
 #endif
diff --git a/src/libc/private_include/libc/file.h b/src/libc/private_include/libc/file.h
index dabeb89..8cb3fa0 100644
--- a/src/libc/private_include/libc/file.h
+++ b/src/libc/private_include/libc/file.h
@@ -1,4 +1,33 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #ifndef LIBC_FILE_H
 #define LIBC_FILE_H
 
+#include <stdio.h>
+
+struct __file
+{
+    int fd, eof, error;
+    char buf[BUFSIZ];
+    size_t i;
+};
+
+extern struct __file *__files[FOPEN_MAX];
+
 #endif
diff --git a/src/libc/src/CMakeLists.txt b/src/libc/src/CMakeLists.txt
index 11e7a3c..cf88cdc 100644
--- a/src/libc/src/CMakeLists.txt
+++ b/src/libc/src/CMakeLists.txt
@@ -15,6 +15,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 target_sources(c PRIVATE
+    _putchar.c
     errno.c
     ta_init.c
 )
@@ -25,6 +26,7 @@ add_subdirectory(stdlib)
 add_subdirectory(string)
 
 if(NOT LIBC_FREESTANDING)
+    target_sources(c PRIVATE malloc_init.c)
     add_subdirectory(time)
     add_subdirectory(unistd)
 endif()
diff --git a/src/libc/src/_putchar.c b/src/libc/src/_putchar.c
new file mode 100644
index 0000000..df797c6
--- /dev/null
+++ b/src/libc/src/_putchar.c
@@ -0,0 +1,24 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+
+void _putchar(const char c)
+{
+    putchar(c);
+}
diff --git a/src/libc/src/malloc_init.c b/src/libc/src/malloc_init.c
new file mode 100644
index 0000000..1ec87e8
--- /dev/null
+++ b/src/libc/src/malloc_init.c
@@ -0,0 +1,29 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <libc/malloc.h>
+#include <tinyalloc.h>
+#include <stdint.h>
+
+void __malloc_init(void)
+{
+    /* README.md states 16 is a "good default value". */
+    if (!ta_init(300, 16, sizeof (intmax_t)))
+        abort();
+}
diff --git a/src/libc/src/ps1/CMakeLists.txt b/src/libc/src/ps1/CMakeLists.txt
index 1bab87a..25d64a4 100644
--- a/src/libc/src/ps1/CMakeLists.txt
+++ b/src/libc/src/ps1/CMakeLists.txt
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 target_sources(c PRIVATE
-    putchar.c
     setjmp.c
 )
 
diff --git a/src/libc/src/stdio/CMakeLists.txt b/src/libc/src/stdio/CMakeLists.txt
index ca590a1..a4a60d9 100644
--- a/src/libc/src/stdio/CMakeLists.txt
+++ b/src/libc/src/stdio/CMakeLists.txt
@@ -15,5 +15,11 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 target_sources(c PRIVATE
+    fopen.c
+    fputc.c
+    fwrite.c
+    putchar.c
+    putc.c
     puts.c
+    streams.c
 )
diff --git a/src/libc/src/stdio/fopen.c b/src/libc/src/stdio/fopen.c
new file mode 100644
index 0000000..4c47f5a
--- /dev/null
+++ b/src/libc/src/stdio/fopen.c
@@ -0,0 +1,95 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <libc/file.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+static int find_free(void)
+{
+    for (size_t i = 0; i < sizeof __files / sizeof *__files; i++)
+        if (!__files[i])
+            return i;
+
+    return -1;
+}
+
+static int convert(const char *mode)
+{
+    int ret = 0;
+
+    if (!mode)
+        return -1;
+    else if (*mode == 'r')
+        ret |= O_RDONLY;
+    else if (*mode == 'w')
+        ret |= O_WRONLY | O_CREAT;
+    else if (*mode == 'a')
+        ret |= O_WRONLY | O_CREAT | O_APPEND;
+
+    if (*++mode == '+')
+        ret |= O_RDWR;
+
+    if (!ret)
+        return -1;
+
+    return ret;
+}
+
+FILE *fopen(const char *const path, const char *const mode)
+{
+    FILE *ret = NULL;
+    int i, flags, fd = -1;
+    mode_t mask;
+
+    if (!path || (flags = convert(mode)) < 0)
+    {
+        errno = EINVAL;
+        goto failure;
+    }
+    else if ((i = find_free()) < 0)
+    {
+        errno = EMFILE;
+        goto failure;
+    }
+
+    mask = umask(0);
+    umask(mask);
+
+    if ((fd = open(path, flags, 0666 & ~mask)) < 0)
+        goto failure;
+    else if (!(ret = malloc(sizeof *ret)))
+        goto failure;
+
+    *ret = (const struct __file){.fd = fd};
+    __files[i] = ret;
+    return ret;
+
+failure:
+
+    if (fd >= 0)
+        close(fd);
+
+    free(ret);
+    return NULL;
+}
diff --git a/src/libc/src/stdio/fputc.c b/src/libc/src/stdio/fputc.c
new file mode 100644
index 0000000..10fe4c6
--- /dev/null
+++ b/src/libc/src/stdio/fputc.c
@@ -0,0 +1,40 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <libc/file.h>
+
+int fputc(const int ic, FILE *const f)
+{
+    const unsigned char c = ic;
+
+    f->buf[f->i++] = c;
+
+    if (c == '\n' || f->i >= sizeof f->buf)
+    {
+        const size_t n = fwrite(f->buf, f->i, 1, f);
+
+        f->i = 0;
+
+        if (!n)
+            return EOF;
+    }
+
+    return c;
+}
diff --git a/src/libc/src/stdio/fwrite.c b/src/libc/src/stdio/fwrite.c
new file mode 100644
index 0000000..96a4daf
--- /dev/null
+++ b/src/libc/src/stdio/fwrite.c
@@ -0,0 +1,50 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <libc/file.h>
+#include <unistd.h>
+
+size_t fwrite(const void *const p, const size_t sz, const size_t nmemb,
+    FILE *const f)
+{
+    size_t ret = 0;
+    const char *b = p;
+
+    for (size_t i = 0; i < nmemb; i++, ret++)
+    {
+        size_t rem = sz;
+
+        while (rem)
+        {
+            const ssize_t n = write(f->fd, b, rem);
+
+            if (n < 0)
+            {
+                f->error = 1;
+                return 0;
+            }
+
+            b += n;
+            rem -= n;
+        }
+    }
+
+    return ret;
+}
diff --git a/src/libc/src/stdio/putc.c b/src/libc/src/stdio/putc.c
new file mode 100644
index 0000000..b8d015d
--- /dev/null
+++ b/src/libc/src/stdio/putc.c
@@ -0,0 +1,25 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+
+int putc(const int c, FILE *const f)
+{
+    return fputc(c, f);
+}
diff --git a/src/libc/src/ps1/putchar.c b/src/libc/src/stdio/putchar.c
index 81c98ec..290ad97 100644
--- a/src/libc/src/ps1/putchar.c
+++ b/src/libc/src/stdio/putchar.c
@@ -20,10 +20,5 @@
 
 int putchar(const int c)
 {
-    return EOF;
-}
-
-void _putchar(const char c)
-{
-    putchar(c);
+    return putc(c, stdout);
 }
diff --git a/src/libc/src/stdio/streams.c b/src/libc/src/stdio/streams.c
new file mode 100644
index 0000000..d88caa1
--- /dev/null
+++ b/src/libc/src/stdio/streams.c
@@ -0,0 +1,24 @@
+/*
+ * wnix, a Unix-like operating system for WebAssembly applications.
+ * Copyright (C) 2025  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <libc/file.h>
+#include <unistd.h>
+
+struct __file *__stdin, *__stdout, *__stderr;
+struct __file *__files[FOPEN_MAX];
diff --git a/src/libc/src/stdlib/malloc.c b/src/libc/src/stdlib/malloc.c
index 786f314..9025491 100644
--- a/src/libc/src/stdlib/malloc.c
+++ b/src/libc/src/stdlib/malloc.c
@@ -20,16 +20,12 @@
 #include <libc/malloc.h>
 #include <tinyalloc.h>
 #include <errno.h>
-#include <stdint.h>
 
 void *__malloc(const size_t n)
 {
     if (!__malloc_ta_init)
     {
-        /* README.md states 16 is a "good default value". */
-        if (!ta_init(300, 16, sizeof (intmax_t)))
-            abort();
-
+        __malloc_init();
         __malloc_ta_init = 1;
     }
 
diff --git a/src/libc/src/unistd/sbrk.c b/src/libc/src/unistd/sbrk.c
index b41c192..5d193da 100644
--- a/src/libc/src/unistd/sbrk.c
+++ b/src/libc/src/unistd/sbrk.c
@@ -25,9 +25,6 @@ static char *base = __bss_end;
 
 void *sbrk(const intptr_t increment)
 {
-
-
-
     if (base + increment >= __ram_end)
         return NULL;
 
diff --git a/src/libc/tinyalloc b/src/libc/tinyalloc
-Subproject fd8128d9b84e362abdbd05fafe252421edee8ab
+Subproject e32da5559962c6131e1f933a245526d699d45cf