Merge pull request #16 from sksat/master

cat実装

Author: sksat

cat/sksat-cat.c

@@ -0,0 +1,369 @@
+// compile: $(CC) sksat-cat.c -o sksat-cat -nostdlib -fno-builtin -fno-stack-protector
+
+#define NULL			0x00
+
+// std types
+typedef _Bool			bool;
+#define	true			1
+#define false			0
+// 64bit
+#define __SIZE_TYPE__		long unsigned int
+typedef long			__kernel_ssize_t;
+
+typedef __SIZE_TYPE__		size_t;
+typedef __kernel_ssize_t	ssize_t;
+
+// my stdlib
+
+// system call
+
+#define TO_STRING(str)	#str
+#define STR(val) TO_STRING(val)
+
+#define NUM_READ	0
+#define NUM_WRITE	1
+#define NUM_OPEN	2
+#define NUM_CLOSE	3
+#define NUM_EXIT	60
+#define NUM_OPENAT	257
+
+#define AT_FDCWD	-100
+
+ssize_t sys_read(unsigned int fd, char *buf, size_t count);
+void sys_write(unsigned int fd, const char *buf, size_t count);
+int  sys_open(const char *fname, int flags, int mode);
+int  sys_close(unsigned int fd);
+void sys_exit(int status);
+
+// file
+#define stdin	0
+#define stdout	1
+#define stderr	2
+
+#define O_RDONLY	0x0000
+#define O_WRONLY	0x0001
+#define O_RDWR		0x0002
+#define O_ACCMODE	0x0003
+
+// funcs
+void* memset(void *buf, int ch, size_t n);
+size_t strlen(const char *str);
+int strcmp(const char *s1, const char *s2);
+void fputs(int fd, const char *str);
+void putchar(const int c);
+void puts(const char *str);
+char* puts_printing(const char *str);
+void puti(const int val);
+
+
+#define BUF_SIZE	256
+
+char output_opt;	// do not initialize here!!!
+#define OPT_END		0b00000001
+#define OPT_NONBLANK	0b00000010
+#define OPT_NUMBER	0b00000100
+#define OPT_SQUEEZE	0b00001000
+#define OPT_TAB		0b00010000
+#define OPT_NOPRINT	0b00100000
+
+int main(int argc, char **argv);
+size_t check_cmdline(const int argc, char **argv);
+void check_option(const char *opt);
+void cat_loop(int fd);
+void print_with_opt(const char *buf);
+void print_newline();
+void error(const char *msg);
+
+// entry point
+asm(
+		".global _start;"
+		"_start:\n"
+		"	xorl %ebp, %ebp;"
+		"	movq 0(%rsp), %rdi;"
+		"	lea 8(%rsp), %rsi;"
+		"	call main");
+
+int main(int argc, char **argv){
+	char buf[BUF_SIZE];
+
+	if(check_cmdline(argc, argv) == 0){
+		cat_loop(stdin);
+		sys_exit(0);
+	}
+
+	for(int n=1;n<argc;n++){
+		int fd;
+		size_t len = strlen(argv[n]);
+
+		if(len == 0) continue;
+
+		if(argv[n][0] == '-' && len  == 1)
+			fd = stdin;
+		else
+			fd = sys_open(argv[n], O_RDONLY, 0);
+		if(fd < 0)
+			error("cannot open file.\n");
+		cat_loop(fd);
+		sys_close(fd);
+	}
+
+	sys_exit(0);
+}
+
+size_t check_cmdline(const int argc, char **argv){
+	size_t fnum = 0;
+	output_opt = 0x00;
+	for(int n=1;n<argc;n++){
+		if(strlen(argv[n]) == 0) continue;
+		if(argv[n][0] != '-'){
+			fnum++;
+			continue;
+		}
+		if(argv[n][1] == '\0'){ // "-" stdin
+			fnum++;
+			continue;
+		}
+		check_option(argv[n]);
+		memset(argv[n], '\0', strlen(argv[n]));
+	}
+	return fnum;
+}
+
+void check_option(const char *opt){
+	bool flg_exit = false;
+	size_t h_num = 1;
+	opt++;
+	if(*opt == '-'){ // --***
+		h_num++;
+		opt++;
+	}
+
+	if((h_num==1 && strcmp(opt, "E")==0) |
+			(h_num==2 && strcmp(opt, "show-ends")==0))
+		output_opt |= OPT_END;
+	else if((h_num==1 && strcmp(opt, "n")==0) |
+			(h_num==2 && strcmp(opt, "number")==0))
+		//error("not implemented option.\n");
+		output_opt |= OPT_NUMBER;
+	else if((h_num==1 && strcmp(opt, "s")==0) |
+		(h_num==2 && strcmp(opt, "squeeze-blank")==0))
+		output_opt |= OPT_SQUEEZE;
+	else if((h_num==1 && strcmp(opt, "T")==0) |
+			(h_num==2 && strcmp(opt, "show-tabs")==0))
+		output_opt |= OPT_TAB;
+	else if(h_num == 2 && strcmp(opt, "help") == 0){
+		flg_exit = true;
+		puts("Usage: ./sksat-cat [OPTION]... [FILE]...\n"
+			"Concatenate FILE(s) to standard output.\n\n"
+			"With no FILE, or when FILE is -, read standard input.\n\n"
+			"  -E, --show-ends          display $ at end of each line\n"
+			"  -n, --number             number all output lines\n"
+			"  -s, --squeeze-blank      suppress repeated empty output lines\n"
+			"  -T, --show-tabs          display TAB characters as ^I\n"
+			"    --help     display this help and exit\n"
+			"    --version  output version information and exit\n"
+			"Examples:\n"
+			"  ./sksat-cat f - g  Output f's contents, then standard input, then g's contents.\n"
+			"  ./sksat-cat        Copy standard input to standard output.\n"
+			"\n");
+	}else if(h_num == 2 && strcmp(opt, "version") == 0){
+		flg_exit = true;
+		puts("sksat-cat 0.1\n"
+			"Copyright (C) 2019 sksat\n"
+			"License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.\n"
+			"This is free software: you are free to change and redistribute it.\n"
+			"There is NO WARRANTY, to the extent permitted by law.\n\n"
+			"Written by sksat <sksat@sfc.wide.ad.jp>\n");
+	}else{
+		flg_exit = true;
+		puts("sksat-cat: unrecognized option '");
+			for(int i=0;i<h_num;i++) puts("-");
+			puts(opt);
+			puts("\'\n");
+		puts("Try \'sksat-cat --help\' for more information.\n");
+	}
+
+	if(flg_exit)
+		sys_exit(0);
+}
+
+void cat_loop(int fd){
+	char buf[BUF_SIZE];
+
+	if(output_opt != 0x00)
+		print_newline();
+
+	for(;;){
+		memset(buf, '\0', BUF_SIZE);
+		if(sys_read(fd, buf, BUF_SIZE-1) == 0)
+			break;
+		if(output_opt != 0x00)
+			print_with_opt(buf);
+		else
+			puts(buf);
+	}
+}
+
+void print_with_opt(const char *buf){
+	static bool last_newline = false;
+	char *s = (char*)buf;
+
+	if(last_newline){
+		print_newline();
+		last_newline = true;
+	}
+
+	for(;;){
+		s = puts_printing(s);
+		if(*s == '\0'){
+			if(*(s-1) == '\n') last_newline = true;
+			break;
+		}
+
+		// non printing
+		switch(*s){
+		case '\n':
+			if(output_opt & OPT_SQUEEZE){
+				char *tmp = s+1;
+				for(;;){
+					if(*tmp!='\n') break;
+					tmp++;
+				}
+
+				if((tmp-s) > 1)
+					print_newline();
+				s = tmp-1;
+			}
+			print_newline();
+			break;
+		case '\t':
+			if(output_opt & OPT_TAB)
+				puts("^I");
+			else
+				putchar('\t');
+			break;
+		}
+		s++;
+	}
+}
+
+void print_newline(){
+	static int line = 1;
+	char *newline_str = "\n";
+
+	if(output_opt & OPT_END)
+		newline_str = "$\n";
+
+	if(line != 1)
+		puts(newline_str);
+
+	if(output_opt & OPT_NUMBER){
+		puts("    ");
+		puti(line);
+		puts("  ");
+	}
+
+	line++;
+}
+
+void error(const char *msg){
+	puts(msg);
+	sys_exit(-1);
+}
+
+// library funcs impl
+
+void* memset(void *buf, int ch, size_t n){
+	int i;
+	for(i=0;i<n;i++){
+		((char*)buf)[i] = ch;
+	}
+	return buf;
+}
+
+size_t strlen(const char *str){
+	size_t len;
+	for(len=0;;len++){
+		if(str[len] == '\0')
+			break;
+	}
+	return len;
+}
+
+int strcmp(const char *s1, const char *s2){
+	size_t l1, l2, len;
+	l1 = strlen(s1);
+	l2 = strlen(s2);
+	len = (l1<l2 ? l1 : l2);
+	for(int n=0;n<len;n++){
+		if(s1[n] != s2[n]) return 1;
+	}
+	return 0;
+}
+
+void fputs(int fd, const char *str){
+	sys_write(fd, str, strlen(str));
+	return;
+}
+
+void putchar(const int c){
+	sys_write(stdout, (const char*)&c, 1);
+}
+
+void puts(const char *str){
+	fputs(stdout, str);
+}
+
+char* puts_printing(const char *str){
+	size_t n=0;
+
+	for(;;n++){
+		const char c = str[n];
+		if(c == '\0' || c == '\n' || c == '\t') break;
+	}
+
+	sys_write(stdout, str, n);
+	return (char*)str+n;
+}
+
+void puti(const int val){
+	if(!val) return;
+	int i= 0;
+	int l = val;
+	while(l/=10) i++;
+
+	puti(val/10);
+	putchar('0'+(val%10));
+}
+
+// system call wrapper impl
+
+ssize_t sys_read(unsigned int fd, char *buf, size_t count){
+	asm volatile (
+			"mov $" STR(NUM_READ) ", %rax;"
+			"syscall");
+}
+
+void sys_write(unsigned int fd, const char *buf, size_t count){
+	asm volatile (
+			"mov $" STR(NUM_WRITE) ", %rax;"
+			"syscall");
+}
+
+int sys_open(const char *fname, int flags, int mode){
+	asm volatile (
+			"mov $" STR(NUM_OPEN) ", %rax;"
+			"syscall");
+}
+
+int  sys_close(unsigned int fd){
+	asm volatile (
+			"mov $" STR(NUM_CLOSE) ", %rax;"
+			"syscall");
+}
+
+void sys_exit(int status){
+	asm volatile (
+			"mov $" STR(NUM_EXIT) ", %rax;"
+			"syscall");
+}