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author Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
date Thu, 05 Apr 2018 11:30:03 +0900
parents
children
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22
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
1 title: 近況報告
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
2 author: Takahiro Shimizu
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
3 profile:
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
4 lang: Japanese
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
5
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
6 # 今週の進捗
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
7
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
8 - xv6をcloneして読み始めました
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
9 - [Xv6, a simple Unix-like teaching operating system](https://pdos.csail.mit.edu/6.828/2017/xv6.html)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
10 - 教科書もありました
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
11 - [xv6 a simple, Unix-like teaching operating system](https://pdos.csail.mit.edu/6.828/2017/xv6/book-rev10.pdf)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
12 - 木金で読み会をやる予定です
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
13
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
14 # systemcall
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
15
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
16 - `user.h` `usys.S`でそれぞれ定義されていました
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
17
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
18 ```c
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
19 // system calls
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
20 int fork(void);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
21 int exit(void) __attribute__((noreturn));
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
22 int wait(void);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
23 int pipe(int*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
24 int write(int, void*, int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
25 int read(int, void*, int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
26 int close(int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
27 int kill(int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
28 int exec(char*, char**);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
29 int open(char*, int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
30 int mknod(char*, short, short);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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31 int unlink(char*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
32 int fstat(int fd, struct stat*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
33 int link(char*, char*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
34 int mkdir(char*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
35 int chdir(char*);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
36 int dup(int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
37 int getpid(void);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
38 char* sbrk(int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
39 int sleep(int);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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40 int uptime(void);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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41 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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42
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
43 # printf
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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44
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
45 - printfは `%d, %x, %p, %s.` のみをサポートしています
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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46 - コンパイラ構成論で書いたような素朴な実装でした
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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47 - print時の進数は `printint` の引数で分けているようです
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
48
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
49 ```c
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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50 void
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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51 printf(int fd, char *fmt, ...)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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52 {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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53 char *s;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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54 int c, i, state;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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55 uint *ap;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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56
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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57 state = 0;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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58 ap = (uint*)(void*)&fmt + 1;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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59 for(i = 0; fmt[i]; i++){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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60 c = fmt[i] & 0xff;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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61 if(state == 0){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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62 if(c == '%'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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63 state = '%';
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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64 } else {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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65 putc(fd, c);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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66 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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67 } else if(state == '%'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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68 if(c == 'd'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
69 printint(fd, *ap, 10, 1);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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70 ap++;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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71 } else if(c == 'x' || c == 'p'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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72 printint(fd, *ap, 16, 0);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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73 ap++;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
74 } else if(c == 's'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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75 s = (char*)*ap;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
76 ap++;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
77 if(s == 0)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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78 s = "(null)";
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
79 while(*s != 0){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
80 putc(fd, *s);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
81 s++;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
82 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
83 } else if(c == 'c'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
84 putc(fd, *ap);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
85 ap++;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
86 } else if(c == '%'){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
87 putc(fd, c);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
88 } else {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
89 // Unknown % sequence. Print it to draw attention.
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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90 putc(fd, '%');
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
91 putc(fd, c);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
92 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
93 state = 0;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
94 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
95 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
96 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
97 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
98
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
99 # sysemcallを呼ぶ前
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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100
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
101 - まだ処理が追いきれていません。
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
102
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
103 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
104 static void
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
105 printint(int fd, int xx, int base, int sgn)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
106 {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
107 static char digits[] = "0123456789ABCDEF";
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
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108 char buf[16];
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
109 int i, neg;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
110 uint x;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
111
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
112 neg = 0;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
113 if(sgn && xx < 0){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
114 neg = 1;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
115 x = -xx;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
116 } else {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
117 x = xx;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
118 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
119
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
120 i = 0;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
121 do{
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
122 buf[i++] = digits[x % base];
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
123 }while((x /= base) != 0);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
124 if(neg)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
125 buf[i++] = '-';
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
126
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
127 while(--i >= 0)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
128 putc(fd, buf[i]);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
129 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
130 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
131
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
132 # putc
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
133
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
134 - 素朴にwriteを読んでいる
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
135
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
136 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
137 static void
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
138 putc(int fd, char c)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
139 {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
140 write(fd, &c, 1);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
141 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
142
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
143 ```
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
144
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
145 # sh
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
146
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
147 - main関数
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
148 - まずforkが入る
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
149 - cd以外はparseしてrunする世界観のようです
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
150
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
151 ```C
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
152 int
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
153 main(void)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
154 {
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
155 static char buf[100];
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
156 int fd;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
157
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
158 // Ensure that three file descriptors are open.
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
159 while((fd = open("console", O_RDWR)) >= 0){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
160 if(fd >= 3){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
161 close(fd);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
162 break;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
163 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
164 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
165
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
166 // Read and run input commands.
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
167 while(getcmd(buf, sizeof(buf)) >= 0){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
168 if(buf[0] == 'c' && buf[1] == 'd' && buf[2] == ' '){
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
169 // Chdir must be called by the parent, not the child.
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
170 buf[strlen(buf)-1] = 0; // chop \n
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
171 if(chdir(buf+3) < 0)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
172 printf(2, "cannot cd %s\n", buf+3);
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
173 continue;
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
174 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
175 if(fork1() == 0)
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
176 runcmd(parsecmd(buf));
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
177 wait();
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
178 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
179 exit();
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
180 }
Takahiro SHIMIZU <anatofuz@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
181 ```