From 21a88dd053069c17b619a89bf2c8beefb672fcd5 Mon Sep 17 00:00:00 2001
From: kaashoek <kaashoek>
Date: Wed, 6 Sep 2006 15:32:21 +0000
Subject: [PATCH] some pipe support in sh bug in proc_wait
---
cat.c | 20 +++---
proc.c | 4 +-
sh.c | 202 ++++++++++++++++++++++++++++++++++++---------------------
3 files changed, 141 insertions(+), 85 deletions(-)
diff --git a/cat.c b/cat.c
index 631bd09..9b2ff11 100644
--- a/cat.c
+++ b/cat.c
@@ -27,17 +27,17 @@ main(int argc, char *argv[])
if (argc <= 1) {
rfile(0);
} else {
- for(i = 1; i < argc; i++){
- fd = open(argv[i], 0);
- if(fd < 0){
- puts("cat: cannot open ");
- puts(argv[i]);
- puts("\n");
- exit();
+ for(i = 1; i < argc; i++){
+ fd = open(argv[i], 0);
+ if(fd < 0){
+ puts("cat: cannot open ");
+ puts(argv[i]);
+ puts("\n");
+ exit();
+ }
+ rfile(fd);
+ close(fd);
}
- rfile(fd);
- close(fd);
- }
}
exit();
diff --git a/proc.c b/proc.c
index 80141db..d90b057 100644
--- a/proc.c
+++ b/proc.c
@@ -371,7 +371,7 @@ proc_wait(void)
havekids = 0;
for(i = 0; i < NPROC; i++){
p = &proc[i];
- if(p->ppid == cp->pid){
+ if(p->state != UNUSED && p->ppid == cp->pid){
if(p->state == ZOMBIE){
// Found one.
kfree(p->mem, p->sz);
@@ -385,7 +385,7 @@ proc_wait(void)
havekids = 1;
}
}
-
+
// No point waiting if we don't have any children.
if(!havekids){
release(&proc_table_lock);
diff --git a/sh.c b/sh.c
index b2905e7..0c9e7e6 100644
--- a/sh.c
+++ b/sh.c
@@ -7,21 +7,28 @@
#define BUFSIZ 512
#define MAXARGS 10
#define MAXNODE 2
+#define MAXCMD 2
-// only allocate nodes for i/o redir; at some point we may have to build a
-// a real parse tree.
-struct node {
+// an embarrassingly naive shell
+
+// some day a real parse tree; for now ad-hoc
+struct ionode {
int token;
char *s;
};
-struct node list[MAXNODE];
-int nextnode;
+struct ionode iolist[MAXNODE];
+int nextio;
-char buf[BUFSIZ];
-char *argv[MAXARGS];
-char argv0buf[BUFSIZ];
-int argc;
+struct cmd {
+ char *argv[MAXARGS];
+ char argv0buf[BUFSIZ];
+ int argc;
+ int token;
+};
+struct cmd cmdlist[MAXCMD];
+int nextcmd;
+char buf[BUFSIZ];
int debug = 0;
int parse(char *s);
@@ -29,7 +36,7 @@ void runcmd(void);
int ioredirection(void);
int gettoken(char *s, char **token);
int _gettoken(char *s, char **p1, char **p2);
-void addnode(int token, char *s);
+void addio(int token, char *s);
int
main(void)
@@ -48,21 +55,25 @@ int
parse(char *s)
{
char *t;
- int c;
+ int c, i;
gettoken(s, 0);
- argc = 0;
- nextnode = 0;
+ nextio = 0;
+ nextcmd = 0;
+ for (i = 0; i < MAXCMD; i++) {
+ cmdlist[i].argc = 0;
+ cmdlist[i].token = 0;
+ }
while (1) {
switch ((c = gettoken(0, &t))) {
case 'w': // Add an argument
- if (argc == MAXARGS) {
+ if (cmdlist[nextcmd].argc >= MAXARGS) {
printf(2, "too many arguments\n");
return -1;
}
- argv[argc++] = t;
+ cmdlist[nextcmd].argv[cmdlist[nextcmd].argc++] = t;
break;
case '<': // Input redirection
@@ -71,7 +82,7 @@ parse(char *s)
printf(2, "syntax error: < not followed by word\n");
return -1;
}
- addnode('<', t);
+ addio('<', t);
break;
case '>': // Output redirection
@@ -80,7 +91,13 @@ parse(char *s)
printf(2, "syntax error: > not followed by word\n");
return -1;
}
- addnode('>', t);
+ addio('>', t);
+ break;
+
+ case ';': // command sequence
+ case '|': // pipe
+ cmdlist[nextcmd].token = c;
+ nextcmd++;
break;
case 0: // String is complete
@@ -98,88 +115,127 @@ parse(char *s)
void
runcmd(void)
{
- int i, r, pid;
+ int c, i, r, pid, tfd;
+ int fdarray[2];
// Return immediately if command line was empty.
- if(argc == 0) {
+ if(cmdlist[0].argc == 0) {
if (debug)
printf(2, "EMPTY COMMAND\n");
return;
}
- // Clean up command line.
- // Read all commands from the filesystem: add an initial '/' to
- // the command name.
- // This essentially acts like 'PATH=/'.
- if (argv[0][0] != '/') {
- argv0buf[0] = '/';
- strcpy(argv0buf + 1, argv[0]);
- argv[0] = argv0buf;
- }
- argv[argc] = 0;
+ for (c = 0; c <= nextcmd; c++) {
+ // Clean up command line.
+ // Read all commands from the filesystem: add an initial '/' to
+ // the command name.
+ // This essentially acts like 'PATH=/'.
+ if (cmdlist[c].argv[0][0] != '/') {
+ cmdlist[c].argv0buf[0] = '/';
+ strcpy(cmdlist[c].argv0buf + 1, cmdlist[c].argv[0]);
+ cmdlist[c].argv[0] = cmdlist[c].argv0buf;
+ }
+ cmdlist[c].argv[cmdlist[c].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);
+ // Print the command.
+ if (debug) {
+ printf(2, "[%d] SPAWN:", getpid());
+ for (i = 0; cmdlist[c].argv[i]; i++)
+ printf(2, " %s", cmdlist[c].argv[i]);
+ for (i = 0; i < nextio; i++) {
+ printf(2, "%c %s", iolist[i].token, iolist[i].s);
+ }
+ printf(2, "\n");
}
- printf(2, "\n");
- }
-
- if (strcmp(argv[0], "/cd") == 0) {
- if (debug) printf (2, "/cd %s is build in\n", argv[1]);
- chdir(argv[1]);
- return;
- }
- pid = fork();
- if (pid == 0) {
- if (ioredirection() < 0)
- exit();
- if ((r = exec(argv0buf, (char**) argv)) < 0) {
- printf(2, "exec %s: %d\n", argv[0], r);
- exit();
+ if (strcmp(cmdlist[c].argv[0], "/cd") == 0) {
+ if (debug) printf (2, "/cd %s is build in\n", cmdlist[c].argv[1]);
+ chdir(cmdlist[c].argv[1]);
+ return;
}
- }
- if (pid > 0) {
- if (debug)
- printf(2, "[%d] WAIT %s\n", getpid(), argv[0]);
- wait();
- 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
ioredirection(void)
{
- int i, fd, dfd;
+ int i, fd;
- for (i = 0; i < nextnode; i++) {
- switch (list[i].token) {
+ for (i = 0; i < nextio; i++) {
+ switch (iolist[i].token) {
case '<':
if (close(0) < 0)
printf(2, "close 0 failed\n");
- if ((fd = open(list[i].s, O_RDONLY)) < 0) {
- printf(2, "failed to open %s for read: %d", list[i].s, fd);
+ if ((fd = open(iolist[i].s, O_RDONLY)) < 0) {
+ printf(2, "failed to open %s for read: %d", iolist[i].s, fd);
return -1;
}
if (debug)
- printf(2, "redirect 0 from %s\n", list[i].s);
+ printf(2, "redirect 0 from %s\n", iolist[i].s);
break;
case '>':
if (close(1) < 0)
printf(2, "close 1 failed\n");
- if ((fd = open(list[i].s, O_WRONLY|O_CREATE)) < 0) {
- printf(2, "failed to open %s for write: %d", list[i].s, fd);
+ if ((fd = open(iolist[i].s, O_WRONLY|O_CREATE)) < 0) {
+ printf(2, "failed to open %s for write: %d", iolist[i].s, fd);
exit();
}
if (debug)
- printf(2, "redirect 1 to %s\n", list[i].s);
+ printf(2, "redirect 1 to %s\n", iolist[i].s);
break;
}
}
@@ -187,16 +243,16 @@ ioredirection(void)
}
void
-addnode(int token, char *s)
+addio(int token, char *s)
{
- if (nextnode >= MAXNODE) {
- printf(2, "addnode: ran out of nodes\n");
+ if (nextio >= MAXNODE) {
+ printf(2, "addio: ran out of nodes\n");
return;
}
- list[nextnode].token = token;
- list[nextnode].s = s;
- nextnode++;
+ iolist[nextio].token = token;
+ iolist[nextio].s = s;
+ nextio++;
}
--
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