sanchayanmaity/xv6-cs450
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

some pipe support in sh

Browse source 
bug in proc_wait
This commit is contained in:
kaashoek 2006-09-06 15:32:21 +00:00
parent d49a2d5386
commit 21a88dd053
3 changed files with 141 additions and 85 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
cat.c
View file

@ -27,17 +27,17 @@ main(int argc, char *argv[])
if (argc <= 1) { if (argc <= 1) {
rfile(0); rfile(0);
} else { } else {
for(i = 1; i < argc; i++){ for(i = 1; i < argc; i++){
fd = open(argv[i], 0); fd = open(argv[i], 0);
if(fd < 0){ if(fd < 0){
puts("cat: cannot open "); puts("cat: cannot open ");
puts(argv[i]); puts(argv[i]);
puts("\n"); puts("\n");
exit(); exit();
}
rfile(fd);
close(fd);
} }
rfile(fd);
close(fd);
}
} }
exit(); exit();

2
proc.c
View file

@ -371,7 +371,7 @@ proc_wait(void)
havekids = 0; havekids = 0;
for(i = 0; i < NPROC; i++){ for(i = 0; i < NPROC; i++){
p = &proc[i]; p = &proc[i];
if(p->ppid == cp->pid){ if(p->state != UNUSED && p->ppid == cp->pid){
if(p->state == ZOMBIE){ if(p->state == ZOMBIE){
// Found one. // Found one.
kfree(p->mem, p->sz); kfree(p->mem, p->sz);

204
sh.c
View file

@ -7,21 +7,28 @@
#define BUFSIZ 512 #define BUFSIZ 512
#define MAXARGS 10 #define MAXARGS 10
#define MAXNODE 2 #define MAXNODE 2
#define MAXCMD 2
// only allocate nodes for i/o redir; at some point we may have to build a // an embarrassingly naive shell
// a real parse tree.
struct node { // some day a real parse tree; for now ad-hoc
struct ionode {
int token; int token;
char *s; char *s;
}; };
struct node list[MAXNODE]; struct ionode iolist[MAXNODE];
int nextnode; int nextio;
struct cmd {
char *argv[MAXARGS];
char argv0buf[BUFSIZ];
int argc;
int token;
};
struct cmd cmdlist[MAXCMD];
int nextcmd;
char buf[BUFSIZ]; char buf[BUFSIZ];
char *argv[MAXARGS];
char argv0buf[BUFSIZ];
int argc;
int debug = 0; int debug = 0;
int parse(char *s); int parse(char *s);
@ -29,7 +36,7 @@ void runcmd(void);
int ioredirection(void); int ioredirection(void);
int gettoken(char *s, char **token); int gettoken(char *s, char **token);
int _gettoken(char *s, char **p1, char **p2); int _gettoken(char *s, char **p1, char **p2);
void addnode(int token, char *s); void addio(int token, char *s);
int int
main(void) main(void)
@ -48,21 +55,25 @@ int
parse(char *s) parse(char *s)
{ {
char *t; char *t;
int c; int c, i;
gettoken(s, 0); gettoken(s, 0);
argc = 0; nextio = 0;
nextnode = 0; nextcmd = 0;
for (i = 0; i < MAXCMD; i++) {
cmdlist[i].argc = 0;
cmdlist[i].token = 0;
}
while (1) { while (1) {
switch ((c = gettoken(0, &t))) { switch ((c = gettoken(0, &t))) {
case 'w': // Add an argument case 'w': // Add an argument
if (argc == MAXARGS) { if (cmdlist[nextcmd].argc >= MAXARGS) {
printf(2, "too many arguments\n"); printf(2, "too many arguments\n");
return -1; return -1;
} }
argv[argc++] = t; cmdlist[nextcmd].argv[cmdlist[nextcmd].argc++] = t;
break; break;
case '<': // Input redirection case '<': // Input redirection
@ -71,7 +82,7 @@ parse(char *s)
printf(2, "syntax error: < not followed by word\n"); printf(2, "syntax error: < not followed by word\n");
return -1; return -1;
} }
addnode('<', t); addio('<', t);
break; break;
case '>': // Output redirection case '>': // Output redirection
@ -80,7 +91,13 @@ parse(char *s)
printf(2, "syntax error: > not followed by word\n"); printf(2, "syntax error: > not followed by word\n");
return -1; return -1;
} }
addnode('>', t); addio('>', t);
break;
case ';': // command sequence
case '|': // pipe
cmdlist[nextcmd].token = c;
nextcmd++;
break; break;
case 0: // String is complete case 0: // String is complete
@ -98,88 +115,127 @@ parse(char *s)
void void
runcmd(void) runcmd(void)
{ {
int i, r, pid; int c, i, r, pid, tfd;
int fdarray[2];
// Return immediately if command line was empty. // Return immediately if command line was empty.
if(argc == 0) { if(cmdlist[0].argc == 0) {
if (debug) if (debug)
printf(2, "EMPTY COMMAND\n"); printf(2, "EMPTY COMMAND\n");
return; return;
} }
// Clean up command line. for (c = 0; c <= nextcmd; c++) {
// Read all commands from the filesystem: add an initial '/' to // Clean up command line.
// the command name. // Read all commands from the filesystem: add an initial '/' to
// This essentially acts like 'PATH=/'. // the command name.
if (argv[0][0] != '/') { // This essentially acts like 'PATH=/'.
argv0buf[0] = '/'; if (cmdlist[c].argv[0][0] != '/') {
strcpy(argv0buf + 1, argv[0]); cmdlist[c].argv0buf[0] = '/';
argv[0] = argv0buf; strcpy(cmdlist[c].argv0buf + 1, cmdlist[c].argv[0]);
} cmdlist[c].argv[0] = cmdlist[c].argv0buf;
argv[argc] = 0;
// Print the command.
if (debug) {
printf(2, "[%d] SPAWN:", getpid());
for (i = 0; argv[i]; i++)
printf(2, " %s", argv[i]);
for (i = 0; i < nextnode; i++) {
printf(2, "%c %s", list[i].token, list[i].s);
} }
printf(2, "\n"); cmdlist[c].argv[cmdlist[c].argc] = 0;
}
if (strcmp(argv[0], "/cd") == 0) { // Print the command.
if (debug) printf (2, "/cd %s is build in\n", argv[1]); if (debug) {
chdir(argv[1]); printf(2, "[%d] SPAWN:", getpid());
return; for (i = 0; cmdlist[c].argv[i]; i++)
} printf(2, " %s", cmdlist[c].argv[i]);
for (i = 0; i < nextio; i++) {
pid = fork(); printf(2, "%c %s", iolist[i].token, iolist[i].s);
if (pid == 0) { }
if (ioredirection() < 0) printf(2, "\n");
exit();
if ((r = exec(argv0buf, (char**) argv)) < 0) {
printf(2, "exec %s: %d\n", argv[0], r);
exit();
} }
}
if (pid > 0) { if (strcmp(cmdlist[c].argv[0], "/cd") == 0) {
if (debug) if (debug) printf (2, "/cd %s is build in\n", cmdlist[c].argv[1]);
printf(2, "[%d] WAIT %s\n", getpid(), argv[0]); chdir(cmdlist[c].argv[1]);
wait(); return;
if (debug) }
printf(2, "[%d] wait finished\n", getpid());
if (cmdlist[c].token == '|')
if (pipe(fdarray) < 0)
printf(2, "cmd %d pipe failed\n", c);
pid = fork();
if (pid == 0) {
if (cmdlist[c].token == '|') {
if (close(1) < 0)
printf(2, "close 1 failed\n");
if ((tfd = dup(fdarray[1])) < 0)
printf(2, "dup failed\n");
if (close(fdarray[0]) < 0)
printf(2, "close fdarray[0] failed\n");
if (close(fdarray[1]) < 0)
printf(2, "close fdarray[1] failed\n");
}
if (c > 0 && cmdlist[c-1].token == '|') {
if (close(0) < 0)
printf(2, "close 0 failed\n");
if ((tfd = dup(fdarray[0])) < 0)
printf(2, "dup failed\n");
if (close(fdarray[0]) < 0)
printf(2, "close fdarray[0] failed\n");
if (close(fdarray[1]) < 0)
printf(2, "close fdarray[1] failed\n");
}
if (ioredirection() < 0)
exit();
if ((r = exec(cmdlist[c].argv0buf, (char**) cmdlist[c].argv)) < 0) {
printf(2, "exec %s: %d\n", cmdlist[c].argv[0], r);
exit();
}
} else if (pid > 0) {
int p;
if (debug)
printf(2, "[%d] FORKED child %d\n", getpid(), pid);
if (c > 0 && cmdlist[c-1].token == '|') {
close(fdarray[0]);
close(fdarray[1]);
}
if (cmdlist[c].token != '|') {
if (debug)
printf(2, "[%d] WAIT for children\n", getpid());
do {
p = wait();
if (debug)
printf(2, "[%d] WAIT child %d finished\n", getpid(), p);
} while (p > 0);
if (debug)
printf(2, "[%d] wait finished\n", getpid());
}
}
} }
} }
int int
ioredirection(void) ioredirection(void)
{ {
int i, fd, dfd; int i, fd;
for (i = 0; i < nextnode; i++) { for (i = 0; i < nextio; i++) {
switch (list[i].token) { switch (iolist[i].token) {
case '<': case '<':
if (close(0) < 0) if (close(0) < 0)
printf(2, "close 0 failed\n"); printf(2, "close 0 failed\n");
if ((fd = open(list[i].s, O_RDONLY)) < 0) { if ((fd = open(iolist[i].s, O_RDONLY)) < 0) {
printf(2, "failed to open %s for read: %d", list[i].s, fd); printf(2, "failed to open %s for read: %d", iolist[i].s, fd);
return -1; return -1;
} }
if (debug) if (debug)
printf(2, "redirect 0 from %s\n", list[i].s); printf(2, "redirect 0 from %s\n", iolist[i].s);
break; break;
case '>': case '>':
if (close(1) < 0) if (close(1) < 0)
printf(2, "close 1 failed\n"); printf(2, "close 1 failed\n");
if ((fd = open(list[i].s, O_WRONLY|O_CREATE)) < 0) { if ((fd = open(iolist[i].s, O_WRONLY|O_CREATE)) < 0) {
printf(2, "failed to open %s for write: %d", list[i].s, fd); printf(2, "failed to open %s for write: %d", iolist[i].s, fd);
exit(); exit();
} }
if (debug) if (debug)
printf(2, "redirect 1 to %s\n", list[i].s); printf(2, "redirect 1 to %s\n", iolist[i].s);
break; break;
} }
} }
@ -187,16 +243,16 @@ ioredirection(void)
} }
void void
addnode(int token, char *s) addio(int token, char *s)
{ {
if (nextnode >= MAXNODE) { if (nextio >= MAXNODE) {
printf(2, "addnode: ran out of nodes\n"); printf(2, "addio: ran out of nodes\n");
return; return;
} }
list[nextnode].token = token; iolist[nextio].token = token;
list[nextnode].s = s; iolist[nextio].s = s;
nextnode++; nextio++;
} }