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-rw-r--r--main.c2
-rw-r--r--sh.c110
2 files changed, 52 insertions, 60 deletions
diff --git a/main.c b/main.c
index 876c20a..2a6ab82 100644
--- a/main.c
+++ b/main.c
@@ -78,7 +78,7 @@ main0(void)
// enable interrupts on the local APIC
lapic_enableintr();
- // Enable interrupts on this processor.
+ // enable interrupts on this processor.
cpus[cpu()].nlock--;
sti();
diff --git a/sh.c b/sh.c
index 4c2397f..2a418bb 100644
--- a/sh.c
+++ b/sh.c
@@ -16,27 +16,26 @@ struct ionode {
int token;
char *s;
};
-struct ionode iolist[MAXNODE];
-int nextio;
struct cmd {
char *argv[MAXARGS];
char argv0buf[BUFSIZ];
int argc;
int token;
+ struct ionode iolist[MAXNODE];
+ struct ionode *io;
};
struct cmd cmdlist[MAXCMD];
-int nextcmd;
+struct cmd *cmd;
char buf[BUFSIZ];
int debug = 0;
int parse(char *s);
void runcmd(void);
-int ioredirection(void);
+int ioredirection(struct ionode *iolist, int nio);
int gettoken(char *s, char **token);
int _gettoken(char *s, char **p1, char **p2);
-void addio(int token, char *s);
int
main(void)
@@ -59,21 +58,21 @@ parse(char *s)
gettoken(s, 0);
- nextio = 0;
- nextcmd = 0;
+ cmd = &cmdlist[0];;
for(i = 0; i < MAXCMD; i++) {
cmdlist[i].argc = 0;
cmdlist[i].token = 0;
+ cmdlist[i].io = cmdlist[i].iolist;
}
while(1) {
switch((c = gettoken(0, &t))) {
case 'w': // Add an argument
- if(cmdlist[nextcmd].argc >= MAXARGS) {
+ if(cmd->argc >= MAXARGS) {
printf(2, "too many arguments\n");
return -1;
}
- cmdlist[nextcmd].argv[cmdlist[nextcmd].argc++] = t;
+ cmd->argv[cmd->argc++] = t;
break;
case '<': // Input redirection
@@ -82,7 +81,9 @@ parse(char *s)
printf(2, "syntax error: < not followed by word\n");
return -1;
}
- addio('<', t);
+ cmd->io->token = '<';
+ cmd->io->s = t;
+ cmd->io++;
break;
case '>': // Output redirection
@@ -91,13 +92,15 @@ parse(char *s)
printf(2, "syntax error: > not followed by word\n");
return -1;
}
- addio('>', t);
+ cmd->io->token = '>';
+ cmd->io->s = t;
+ cmd->io++;
break;
case ';': // command sequence
case '|': // pipe
- cmdlist[nextcmd].token = c;
- nextcmd++;
+ cmd->token = c;
+ cmd++;
break;
case 0: // String is complete
@@ -115,8 +118,10 @@ parse(char *s)
void
runcmd(void)
{
- int c, i, r, pid, tfd;
+ int i, r, pid, tfd;
int fdarray[2];
+ struct cmd *c;
+ struct ionode *io;
// Return immediately if command line was empty.
if(cmdlist[0].argc == 0) {
@@ -125,43 +130,43 @@ runcmd(void)
return;
}
- for(c = 0; c <= nextcmd; c++) {
+ for(c = &cmdlist[0]; c <= cmd; 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;
+ if(c->argv[0][0] != '/') {
+ c->argv0buf[0] = '/';
+ strcpy(c->argv0buf + 1, c->argv[0]);
+ c->argv[0] = c->argv0buf;
}
- cmdlist[c].argv[cmdlist[c].argc] = 0;
+ c->argv[c->argc] = 0;
// 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);
+ for(i = 0; c->argv[i]; i++)
+ printf(2, " %s", c->argv[i]);
+ for(io = c->iolist; io <= c->io; io++) {
+ printf(2, "%c %s", io->token, io->s);
}
printf(2, "\n");
}
- if(strcmp(cmdlist[c].argv[0], "/cd") == 0) {
+ if(strcmp(c->argv[0], "/cd") == 0) {
if(debug)
- printf (2, "/cd %s is build in\n", cmdlist[c].argv[1]);
- chdir(cmdlist[c].argv[1]);
+ printf (2, "/cd %s is build in\n", c->argv[1]);
+ chdir(c->argv[1]);
return;
}
- if(cmdlist[c].token == '|')
+ if(c->token == '|')
if(pipe(fdarray) < 0)
printf(2, "cmd %d pipe failed\n", c);
pid = fork();
if(pid == 0) {
- if(cmdlist[c].token == '|') {
+ if(c->token == '|') {
if(close(1) < 0)
printf(2, "close 1 failed\n");
if((tfd = dup(fdarray[1])) < 0)
@@ -171,7 +176,7 @@ runcmd(void)
if(close(fdarray[1]) < 0)
printf(2, "close fdarray[1] failed\n");
}
- if(c > 0 && cmdlist[c-1].token == '|') {
+ if(c > cmdlist && (c-1)->token == '|') {
if(close(0) < 0)
printf(2, "close 0 failed\n");
if((tfd = dup(fdarray[0])) < 0)
@@ -181,10 +186,10 @@ runcmd(void)
if(close(fdarray[1]) < 0)
printf(2, "close fdarray[1] failed\n");
}
- if(ioredirection() < 0)
+ if(ioredirection(c->iolist, c->io - c->iolist) < 0)
exit();
- if((r = exec(cmdlist[c].argv0buf, (char**) cmdlist[c].argv)) < 0) {
- printf(2, "exec %s: %d\n", cmdlist[c].argv[0], r);
+ if((r = exec(c->argv0buf, (char**) c->argv)) < 0) {
+ printf(2, "exec %s: %d\n", c->argv[0], r);
exit();
}
} else if(pid > 0) {
@@ -192,11 +197,11 @@ runcmd(void)
if(debug)
printf(2, "[%d] FORKED child %d\n", getpid(), pid);
- if(c > 0 && cmdlist[c-1].token == '|') {
+ if(c > cmdlist && (c-1)->token == '|') {
close(fdarray[0]);
close(fdarray[1]);
}
- if(cmdlist[c].token != '|') {
+ if(c->token != '|') {
if(debug)
printf(2, "[%d] WAIT for children\n", getpid());
do {
@@ -212,51 +217,38 @@ runcmd(void)
}
int
-ioredirection(void)
+ioredirection(struct ionode *iolist, int nio)
{
- int i, fd;
+ int fd;
+ struct ionode *io;
- for(i = 0; i < nextio; i++) {
- switch(iolist[i].token) {
+ for(io = iolist; io < &iolist[nio]; io++) {
+ switch(io->token) {
case '<':
if(close(0) < 0)
printf(2, "close 0 failed\n");
- if((fd = open(iolist[i].s, O_RDONLY)) < 0) {
- printf(2, "failed to open %s for read: %d", iolist[i].s, fd);
+ if((fd = open(io->s, O_RDONLY)) < 0) {
+ printf(2, "failed to open %s for read: %d", io->s, fd);
return -1;
}
if(debug)
- printf(2, "redirect 0 from %s\n", iolist[i].s);
+ printf(2, "redirect 0 from %s\n", io->s);
break;
case '>':
if(close(1) < 0)
printf(2, "close 1 failed\n");
- if((fd = open(iolist[i].s, O_WRONLY|O_CREATE)) < 0) {
- printf(2, "failed to open %s for write: %d", iolist[i].s, fd);
+ if((fd = open(io->s, O_WRONLY|O_CREATE)) < 0) {
+ printf(2, "failed to open %s for write: %d", io->s, fd);
exit();
}
if(debug)
- printf(2, "redirect 1 to %s\n", iolist[i].s);
+ printf(2, "redirect 1 to %s\n", io->s);
break;
}
}
return 0;
}
-void
-addio(int token, char *s)
-{
- if(nextio >= MAXNODE) {
- printf(2, "addio: ran out of nodes\n");
- return;
- }
-
- iolist[nextio].token = token;
- iolist[nextio].s = s;
- nextio++;
-}
-
-
// gettoken(s, 0) prepares gettoken for subsequent calls and returns 0.
// gettoken(0, token) parses a shell token from the previously set string,
// null-terminates that token, stores the token pointer in '*token',
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