iostats: bring back standard filedescriptor spying

diff --git a/sys/src/cmd/iostats.c b/sys/src/cmd/iostats.c
index 022eb16c9b619eee1892deef976819c5f5997549..5f96afa35065b05218becf0b6a254995e8ff666d 100644 (file)
--- a/sys/src/cmd/iostats.c
+++ b/sys/src/cmd/iostats.c
@@ -263,6 +263,7 @@ main(int argc, char **argv)
        char buf[64*1024];
        float brpsec, bwpsec, bppsec;
        int cpid, fspid, rspid, dbg, n, mflag;
+       char *fds[3];
        File *fs;
        Req *r, **rr;
 
@@ -292,11 +293,20 @@ main(int argc, char **argv)
        if(pipe(pfd) < 0)
                sysfatal("pipe");
 
+       /* dup std fds to be inherited to exportfs */
+       fds[0] = smprint("/fd/%d", dup(0, -1));
+       fds[1] = smprint("/fd/%d", dup(1, -1));
+       fds[2] = smprint("/fd/%d", dup(2, -1));
+
        switch(cpid = fork()) {
        case -1:
                sysfatal("fork");
        case 0:
                close(pfd[1]);
+               close(atoi(strrchr(fds[0], '/')+1));
+               close(atoi(strrchr(fds[1], '/')+1));
+               close(atoi(strrchr(fds[2], '/')+1));
+
                if(getwd(buf, sizeof(buf)) == 0)
                        sysfatal("no working directory");
 
@@ -305,6 +315,11 @@ main(int argc, char **argv)
                if(mount(pfd[0], -1, "/", mflag, "") < 0)
                        sysfatal("mount /");
 
+               /* replace std fds with the exported ones */
+               close(0); open(fds[0], OREAD);
+               close(1); open(fds[1], OWRITE);
+               close(2); open(fds[2], OWRITE);
+
                bind("#c/pid", "/dev/pid", MREPL);
                bind("#c/ppid", "/dev/ppid", MREPL);
                bind("#e", "/env", MREPL|MCREATE);
@@ -322,21 +337,6 @@ main(int argc, char **argv)
 
        /* isolate us from interrupts */
        rfork(RFNOTEG);
-       switch(fspid = fork()) {
-       default:
-               while(cpid != waitpid())
-                       ;
-               postnote(PNPROC, fspid, DONESTR);
-               while(fspid != waitpid())
-                       ;
-               exits(0);
-       case -1:
-               sysfatal("fork");
-       case 0:
-               notify(catcher);
-               break;
-       }
-
        if(pipe(efd) < 0)
                sysfatal("pipe");
 
@@ -344,6 +344,9 @@ main(int argc, char **argv)
        switch(fork()) {
        default:
                close(efd[0]);
+               close(atoi(strrchr(fds[0], '/')+1));
+               close(atoi(strrchr(fds[1], '/')+1));
+               close(atoi(strrchr(fds[2], '/')+1));
                break;
        case -1:
                sysfatal("fork");
@@ -359,6 +362,21 @@ main(int argc, char **argv)
                exits(0);
        }
 
+       switch(fspid = fork()) {
+       default:
+               while(cpid != waitpid())
+                       ;
+               postnote(PNPROC, fspid, DONESTR);
+               while(fspid != waitpid())
+                       ;
+               exits(0);
+       case -1:
+               sysfatal("fork");
+       case 0:
+               notify(catcher);
+               break;
+       }
+
        fmtinstall('F', fcallfmt);
 
        stats->rpc[Tversion].name = "version";
@@ -521,6 +539,14 @@ main(int argc, char **argv)
        for(fs = stats->file; fs < &stats->file[Maxfile]; fs++){
                if(fs->nopen == 0)
                        break;
+
+               if(strcmp(fs->path, fds[0]) == 0)
+                       fs->path = "stdin";
+               else if(strcmp(fs->path, fds[1]) == 0)
+                       fs->path = "stdout";
+               else if(strcmp(fs->path, fds[2]) == 0)
+                       fs->path = "stderr";
+
                fprint(2, "%5lud %8lud %8llud %8lud %8llud %s\n",
                        fs->nopen,
                        fs->nread, fs->bread,