user/libc: fread, fwrite, fclose

6 files changed, 79 insertions, 42 deletions

diff --git a/src/shared/include/camellia/errno.h b/src/shared/include/camellia/errno.h
index a0b5731..a269fa3 100644
--- a/src/shared/include/camellia/errno.h
+++ b/src/shared/include/camellia/errno.h
@@ -1,3 +1,4 @@
 #pragma once
 
 #define EFAULT 2
+#define EBADF 3 /* Invalid file descriptor. */
diff --git a/src/user/app/init/shell.c b/src/user/app/init/shell.c
index 795bb5e..253acce 100644
--- a/src/user/app/init/shell.c
+++ b/src/user/app/init/shell.c
@@ -38,7 +38,7 @@ static char *strtrim(char *s) {
 static int readline(char *buf, size_t max) {
 	char c = '\0';
 	size_t pos = 0;
-	while (pos < (max-1) && c != '\n' && file_read(stdin, &c, 1))
+	while (pos < (max-1) && c != '\n' && fread(&c, 1, 1, stdin))
 		buf[pos++] = c;
 	buf[pos++] = '\0';
 	return pos;
@@ -73,16 +73,16 @@ static void cmd_cat_ls(const char *args, bool ls) {
 	}
 
 	while (!file->eof) {
-		int len = file_read(file, buf, sizeof buf);
+		int len = fread(buf, 1, sizeof buf, file);
 		if (len <= 0) break;
 
 		if (ls) {
 			for (int i = 0; i < len; i++)
 				if (buf[i] == '\0') buf[i] = '\n';
 		}
-		file_write(stdout, buf, len);
+		fwrite(buf, 1, len, stdout);
 	}
-	file_close(file);
+	fclose(file);
 }
 
 static void cmd_hexdump(const char *args) {
@@ -166,7 +166,7 @@ void shell_loop(void) {
 					printf("couldn't open file\n");
 				} else {
 					elf_execf(file);
-					file_close(file);
+					fclose(file);
 					printf("elf_execf failed\n");
 				}
 			} else if (!strcmp(cmd, "cat")) {
diff --git a/src/user/lib/elfload.c b/src/user/lib/elfload.c
index 75c1162..b73dfe5 100644
--- a/src/user/lib/elfload.c
+++ b/src/user/lib/elfload.c
@@ -11,17 +11,9 @@ void elf_execf(FILE *f) {
 	const size_t cap = 0x60000;
 	size_t pos = 0;
 	void *buf = malloc(cap); // TODO a way to get file size
-	if (!buf) goto fail;
+	if (buf && fread(buf, 1, cap - pos, f))
+		elf_exec(buf);
 
-	while (!f->eof) {
-		long ret = file_read(f, buf, cap - pos);
-		if (ret < 0) goto fail;
-		pos += ret;
-		if (pos >= cap) goto fail;
-	}
-	elf_exec(buf);
-
-fail:
 	free(buf);
 }
 
diff --git a/src/user/lib/include/bits/file.h b/src/user/lib/include/bits/file.h
index 74a8c17..e50d402 100644
--- a/src/user/lib/include/bits/file.h
+++ b/src/user/lib/include/bits/file.h
@@ -5,5 +5,6 @@ struct FILE {
 	int fd;
 	int pos;
 	bool eof;
+	bool error;
 };
 typedef struct FILE FILE;
diff --git a/src/user/lib/include/stdio.h b/src/user/lib/include/stdio.h
index 9d6921a..2f0746f 100644
--- a/src/user/lib/include/stdio.h
+++ b/src/user/lib/include/stdio.h
@@ -2,6 +2,8 @@
 #include <bits/file.h>
 #include <stddef.h>
 
+#define EOF (-1)
+
 int printf(const char *fmt, ...);
 int snprintf(char *str, size_t len, const char *fmt, ...);
 
@@ -11,9 +13,9 @@ int _klogf(const char *fmt, ...); // for kernel debugging only
 extern FILE *const stdin, *const stdout;
 
 FILE *fopen(const char *path, const char *mode);
-FILE *freopen(const char *path, const char *mode, FILE*);
+FILE *freopen(const char *path, const char *mode, FILE *);
 FILE *fdopen(int fd, const char *mode);
-FILE *file_clone(const FILE*);
-int file_read(FILE*, char *buf, size_t len);
-int file_write(FILE*, const char *buf, size_t len);
-void file_close(FILE*);
+FILE *file_clone(const FILE *);
+size_t fread(void *restrict ptr, size_t size, size_t nitems, FILE *restrict);
+size_t fwrite(const void *restrict ptr, size_t size, size_t nitems, FILE *restrict);
+int fclose(FILE *);
diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 0eb145f..cd2ec90 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -15,7 +15,7 @@ FILE *const stdin = &_stdin_null, *const stdout = &_stdout_null;
 int errno = 0;
 
 static void backend_file(void *arg, const char *buf, size_t len) {
-	file_write((FILE*)arg, buf, len);
+	fwrite(buf, 1, len, (FILE *)arg);
 }
 
 int printf(const char *fmt, ...) {
@@ -93,13 +93,13 @@ FILE *fopen(const char *path, const char *mode) {
 	}
 	f->pos = f2->pos;
 	f->eof = f2->eof;
-	file_close(f2);
+	fclose(f2);
 	return f;
 
 fail2:
-	file_close(f2);
+	fclose(f2);
 fail:
-	file_close(f);
+	fclose(f);
 	return NULL;
 }
 
@@ -110,6 +110,7 @@ FILE *fdopen(int fd, const char *mode) {
 	f->pos = mode[0] == 'a' ? -1 : 0;
 	f->eof = false;
 	f->fd = fd;
+	f->error = false;
 	return f;
 }
 
@@ -129,34 +130,74 @@ FILE *file_clone(const FILE *f) {
 	return f2;
 }
 
-int file_read(FILE *f, char *buf, size_t len) {
-	if (f->fd < 0) return -1;
-
-	int res = _syscall_read(f->fd, buf, len, f->pos);
-	if (res < 0) return res;
-	if (res == 0 && len > 0) f->eof = true;
-
-	bool negative_pos = f->pos < 0;
-	f->pos += res;
-	if (negative_pos && f->pos >= 0)
+static void fadvance(long amt, FILE *f) {
+	bool pos_neg = f->pos < 0;
+	f->pos += amt;
+	if (pos_neg && f->pos >= 0)
 		f->pos = -1;
+}
+
+size_t fread(void *restrict ptr, size_t size, size_t nitems, FILE *restrict f) {
+	size_t total = size*nitems, pos = 0;
+	unsigned char *buf = ptr;
 
-	return res;
+	if (f->fd < 0) {
+		errno = EBADF;
+		return 0;
+	}
+	if (size == 0)
+		return 0;
+
+	while (pos < total) {
+		long res = _syscall_read(f->fd, buf + pos, total - pos, f->pos);
+		if (res < 0) {
+			f->error = true;
+			errno = -res;
+			return pos/size;
+		} else if (res == 0) {
+			f->eof = true;
+			return pos/size;
+		} else {
+			pos += res;
+			fadvance(res, f);
+		}
+	}
+	return nitems;
 }
 
-int file_write(FILE *f, const char *buf, size_t len) {
-	if (f->fd < 0) return -1;
+size_t fwrite(const void *restrict ptr, size_t size, size_t nitems, FILE *restrict f) {
+	size_t total = size*nitems, pos = 0;
+	const unsigned char *buf = ptr;
 
-	int res = _syscall_write(f->fd, buf, len, f->pos);
-	if (res < 0) return res;
-	f->pos += res;
-	return res;
+	if (f->fd < 0) {
+		errno = EBADF;
+		return 0;
+	}
+	if (size == 0)
+		return 0;
+
+	while (pos < total) {
+		long res = _syscall_write(f->fd, buf + pos, total - pos, f->pos);
+		if (res < 0) {
+			f->error = true;
+			errno = -res;
+			return pos/size;
+		} else if (res == 0) {
+			f->eof = true;
+			return pos/size;
+		} else {
+			pos += res;
+			fadvance(res, f);
+		}
+	}
+	return nitems;
 }
 
-void file_close(FILE *f) {
+int fclose(FILE *f) {
 	if (f->fd > 0) close(f->fd);
 	if (f != &_stdin_null && f != &_stdout_null)
 		free(f);
+	return 0;
 }