Adds fopen(), fwrite(), fclose()

.gitignore

@@ -1,3 +1,4 @@
 *.lst
 *.o
+*.txt
 tests

console.asm

@@ -1,3 +1,4 @@
+extern	NR_write
 extern	strlen
 
 section .rodata
@@ -14,7 +15,7 @@ print:
 
 	call	strlen
 	mov	rdx, rax
-	mov	rax, 1
+	mov	rax, NR_write
 	mov	rsi, rdi
 	mov	rdi, 1
 	syscall
@@ -30,7 +31,7 @@ puts:
 	mov	r10, rdi
 	call	print
 	mov	rdi, r10
-	mov	rax, 1
+	mov	rax, NR_write
 	mov	rdi, 1
 	mov	rsi, NL
 	mov	rdx, 1

constants.asm

@@ -1,6 +1,18 @@
 section .rodata
+	global	NR_read
+	global	NR_write
+	global	NR_open
+	global	NR_close
+	
 	global	EOS
 	global	NL
 
+	;syscalls
+	NR_read		equ	0
+	NR_write	equ	1
+	NR_open		equ	2
+	NR_close	equ	3
+
+	;ascii
 	EOS		equ	0x0
 	NL		equ	0xA

file.asm

@@ -0,0 +1,110 @@
+extern	NR_read
+extern	NR_write
+extern	NR_open
+extern	NR_close
+
+extern	strlen
+
+section .rodata
+	O_RDONLY	equ	00000000q
+	O_WRONLY	equ	00000001q
+	O_RDWR		equ	00000002q
+	O_CREAT		equ	00000100q
+	O_TRUNC		equ	00001000q
+	O_APPEND	equ	00002000q
+	
+section .text
+	global	fopen
+	global	fclose
+	global	fwrite
+
+;----- fopen(const char *filename, const char *mode) -----;
+; return value: pointer to file or NULL if file failed to open
+;              ┌─────────────┬───────────────────────────────┐
+;              │fopen() mode │ open() flags                  │
+;              ├─────────────┼───────────────────────────────┤
+;              │     r       │ O_RDONLY                      │
+;              ├─────────────┼───────────────────────────────┤
+;              │     w       │ O_WRONLY | O_CREAT | O_TRUNC  │
+;              ├─────────────┼───────────────────────────────┤
+;              │     a       │ O_WRONLY | O_CREAT | O_APPEND │
+;              ├─────────────┼───────────────────────────────┤
+;              │     R       │ O_RDWR                        │
+;              ├─────────────┼───────────────────────────────┤
+;              │     W       │ O_RDWR | O_CREAT | O_TRUNC    │
+;              ├─────────────┼───────────────────────────────┤
+;              │     A       │ O_RDWR | O_CREAT | O_APPEND   │
+;              └─────────────┴───────────────────────────────┘
+fopen:
+	push	rbp
+	mov	rbp, rsp
+
+	cmp	byte [rsi], 'r'
+	je	.setMode_r
+	cmp	byte [rsi], 'w'
+	je	.setMode_w
+	cmp	byte [rsi], 'a'
+	je	.setMode_a
+	cmp	byte [rsi], 'R'
+	je	.setMode_R
+	cmp	byte [rsi], 'W'
+	je	.setMode_W
+	cmp	byte [rsi], 'A'
+	je	.setMode_A
+	xor	rax, rax
+	jmp	.quit
+
+	.setMode_r:
+		mov	rsi, O_RDONLY
+		jmp	.open
+	.setMode_w:
+		mov	rsi, O_WRONLY | O_CREAT | O_TRUNC
+		jmp	.open
+	.setMode_a:
+		mov	rsi, O_WRONLY | O_CREAT | O_APPEND
+		jmp	.open
+	.setMode_R:
+		mov	rsi, O_RDWR
+		jmp	.open
+	.setMode_W:
+		mov	rsi, O_RDWR | O_CREAT | O_TRUNC
+		jmp	.open
+	.setMode_A:
+		mov	rsi, O_RDWR | O_CREAT | O_APPEND
+		jmp	.open
+
+	.open:
+	mov	rax, NR_open
+	syscall
+
+	.quit:
+	leave
+	ret
+;----- fclose(FILE* fp) -----;
+; return value: 0 on success, below 0 otherwise
+fclose:
+	push	rbp
+	mov	rbp, rsp
+
+	mov	rax, NR_close
+	syscall
+
+	leave
+	ret
+;----- fwrite(FILE* fp, char* str) -----;
+; writes a string to opened file
+; return value: 0 on success, below 0 otherwise
+fwrite:
+	push	rbp
+	mov	rbp, rsp
+
+	mov	r9, rdi
+	mov	rdi, rsi
+	call	strlen
+	mov	rdx, rax
+	mov	rax, NR_write
+	mov	rdi, r9
+	syscall
+
+	leave
+	ret

makefile

@@ -1,5 +1,5 @@
-tests: tests.o constants.o core.o console.o string.o
+tests: tests.o constants.o core.o console.o string.o file.o
-	gcc tests.o constants.o core.o console.o string.o -o tests -no-pie -z noexecstack
+	gcc tests.o constants.o core.o console.o string.o file.o -o tests -no-pie -z noexecstack
 tests.o: tests.asm
 	nasm tests.asm -f elf64 -l tests.lst -g -F dwarf
 constants.o: constants.asm
@@ -10,6 +10,8 @@ console.o: console.asm
 	nasm console.asm -f elf64 -l console.lst -g -F dwarf
 string.o: string.asm
 	nasm string.asm -f elf64 -l string.lst -g -F dwarf
+file.o: file.asm
+	nasm file.asm -f elf64 -l file.lst -g -F dwarf
 
 clean:
-	rm -f tests *.lst *.o
+	rm -f tests *.lst *.o testFile1.txt

string.asm

@@ -44,8 +44,8 @@ strcpy:
 
 	.0f:
 	mov	byte [r11], 0x0
-	cmp	rcx, 0
+	test	rcx, rcx
-	je	.quit
+	jz	.quit
 	mov	rax, rdi
 
 	.quit:

tests.asm

@@ -23,6 +23,10 @@ extern	strclr
 extern	strlclr
 extern	strcat
 extern	strcmp
+;file.asm
+extern	fopen
+extern	fclose
+extern	fwrite
 
 section	.rodata
 	PRINT_nums	equ	1
@@ -42,6 +46,7 @@ section	.rodata
 	TEST_tolower	equ	1
 	TEST_toupper	equ	1
 	TEST_strcmp	equ	1
+	TEST_file1	equ	1
 
 	num1		dq	69
 	num2		dq	0xFFFFFF
@@ -141,6 +146,16 @@ section	.rodata
 	msgStrcmp4	db	"TEST strcmp(str4, str1): %d",NL,EOS
 	msgStrcmp5	db	"TEST strcmp(str1, str4): %d",NL,EOS
 	msgStrcmp6	db	"TEST strcmp(str1, str1): %d",NL,EOS
+	; fopen(), fwrite(), fclose()
+	testFile1	db	"testFile1.txt",EOS
+	fileStr1	db	"Hello file world!",EOS
+	fileMode_w	db	"w",EOS
+	msgFileB	db	NL,"# fopen(), fwrite(), fclose()",EOS
+	msgFileB1	db	"TEST fopen('testFile1.txt', 'w'): %d",NL,EOS
+	msgFileB2	db	"TEST fwrite(filePointer1, fileStr1): %d",NL,EOS
+	msgFileB3	db	"TEST fclose(filePointer1): %d",NL,EOS
+section .data
+	filePointer1	dq	0
 section .bss
 	strBuff1	resb	32
 	strBuff2	resb	8
@@ -712,6 +727,37 @@ main:
 	lea	rdi, [rel msgStrcmp6]
 	call	printf
 %ENDIF
+%IF TEST_file1
+	lea	rdi, [rel msgFileB]
+	call	puts
+
+	; TEST: fopen()
+	lea	rdi, [rel testFile1]
+	lea	rsi, [rel fileMode_w]
+	call	fopen
+	mov	r15, rax ;store filepointer to R15
+	mov	rsi, rax
+	xor	rax, rax
+	lea	rdi, [rel msgFileB1]
+	call	printf
+
+	; TEST: fwrite()
+	mov	rdi, r15
+	lea	rsi, [fileStr1]
+	call	fwrite
+	mov	rsi, rax
+	xor	rax, rax
+	lea	rdi, [rel msgFileB2]
+	call	printf
+
+	; TEST: fclose()
+	mov	rdi, r15
+	call	fclose
+	mov	rsi, rax
+	xor	rax, rax
+	lea	rdi, [rel msgFileB3]
+	call	printf
+%ENDIF
 
 	leave
 	ret