Patch from Jonas Holmberg, adjusted by Robert Schwebel, and

later re-adjusted by me to fix msh backtick handling

1 files changed, 144 insertions, 55 deletions

diff --git a/shell/msh.c b/shell/msh.c
index 60fc1dc34..53f643de1 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -5,6 +5,11 @@
  * This version of the Minix shell was adapted for use in busybox
  * by Erik Andersen <andersee@debian.org>
  *
+ * - backtick expansion did not work properly
+ *   Jonas Holmberg <jonas.holmberg@axis.com>
+ *   Robert Schwebel <r.schwebel@pengutronix.de>
+ *   Erik Andersen <andersee@debian.org>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -222,7 +227,7 @@ static char *space (int n );
 static char *strsave (char *s, int a );
 static char *evalstr (char *cp, int f );
 static char *putn (int n );
-static char *itoa (unsigned u, int n );
+static char *itoa (int n );
 static char *unquote (char *as );
 static struct var *lookup (char *n );
 static int rlookup (char *n );
@@ -664,7 +669,6 @@ static int	heedint =1;
 static struct env e ={line, iostack, iostack-1, (xint *)NULL, FDBASE, (struct env *)NULL};
 static void (*qflag)(int) = SIG_IGN;
 static char     shellname[] = "/bin/sh";
-static char     search[] = ":/bin:/usr/bin";
 static  int     startl;
 static  int     peeksym;
 static  int     nlseen;
@@ -687,7 +691,6 @@ static void * brkaddr;
 static char * current_prompt;
 #endif
 
-
 /* -------- sh.c -------- */
 /*
  * shell
@@ -722,11 +725,15 @@ extern int msh_main(int argc, char **argv)
                 setval(homedir, "/");
         export(homedir);
 
-        setval(lookup("$"), itoa(getpid(), 5));
+        setval(lookup("$"), putn(getpid()));
 
         path = lookup("PATH");
-        if (path->value == null)
-                setval(path, search);
+        if (path->value == null) {
+                if (geteuid() == 0)
+                        setval(path, "/sbin:/bin:/usr/sbin:/usr/bin");
+                else
+                        setval(path, "/bin:/usr/bin");
+        }
         export(path);
 
         ifs = lookup("IFS");
@@ -858,7 +865,7 @@ setdash()
 
         cp = m;
         for (c='a'; c<='z'; c++)
-                if (flag[c])
+                if (flag[(int)c])
                         *cp++ = c;
         *cp = 0;
         setval(lookup("-"), m);
@@ -1047,32 +1054,16 @@ static char *
 putn(n)
 register int n;
 {
-        return(itoa(n, -1));
+        return(itoa(n));
 }
 
 static char *
-itoa(u, n)
-register unsigned u;
-int n;
+itoa(n)
+register int n;
 {
-        register char *cp;
         static char s[20];
-        int m;
-
-        m = 0;
-        if (n < 0 && (int) u < 0) {
-                m++;
-                u = -u;
-        }
-        cp = s+sizeof(s);
-        *--cp = 0;
-        do {
-                *--cp = u%10 + '0';
-                u /= 10;
-        } while (--n > 0 || u);
-        if (m)
-                *--cp = '-';
-        return(cp);
+        snprintf(s, sizeof(s), "%u", n);
+        return(s);
 }
 
 static void
@@ -2326,6 +2317,9 @@ int act;
 
         switch(t->type) {
         case TPAREN:
+                rv = execute(t->left, pin, pout, 0);
+                break;
+                        
         case TCOM:
                 {
                         int child;
@@ -2877,12 +2871,12 @@ char *c, **v, **envp;
                         *v = e.linep;
                         tp = *--v;
                         *v = e.linep;
-                        execve("/bin/sh", v, envp);
+                        execve(shellname, v, envp);
                         *v = tp;
                         return("no Shell");
 
                 case ENOMEM:
-                        return("program too big");
+                        return((char*)memory_exhausted);
 
                 case E2BIG:
                         return("argument list too long");
@@ -3643,7 +3637,7 @@ loop:
  */
 static int
 subgetc(ec, quoted)
-register int ec;
+register char ec;
 int quoted;
 {
         register char c;
@@ -3770,59 +3764,154 @@ int quoted;
 /*
  * Run the command in `...` and read its output.
  */
+
 static int
 grave(quoted)
 int quoted;
 {
-        register int i;
         char *cp;
+        register int i;
+        int j;
         int pf[2];
+        static char child_cmd[LINELIM];
+        char *src;
+        char *dest;
+        int count;
+        int ignore;
+        int ignore_once;
+        char *argument_list[4];
 
 #if __GNUC__
         /* Avoid longjmp clobbering */
         (void) &cp;
 #endif
+        
         for (cp = e.iop->argp->aword; *cp != '`'; cp++)
                 if (*cp == 0) {
                         err("no closing `");
                         return(0);
                 }
+
+        /* string copy with dollar expansion */
+        src = e.iop->argp->aword;
+        dest = child_cmd;
+        count = 0;
+        ignore = 0;
+        ignore_once = 0;
+        while ((*src != '`') && (count < LINELIM)) {
+                if (*src == '\'')
+                        ignore = !ignore;
+                if (*src == '\\')
+                        ignore_once = 1;
+                if (*src == '$' && !ignore && !ignore_once) {
+                        struct var *vp;
+                        char var_name[LINELIM];
+                        char alt_value[LINELIM];
+                        int var_index = 0;
+                        int alt_index = 0;
+                        char operator = 0;
+                        int braces = 0;
+                        char *value;
+
+                        src++;
+                        if (*src == '{') {
+                                braces = 1;
+                                src++;
+                        }
+
+                        var_name[var_index++] = *src++;
+                        while (isalnum(*src))
+                                var_name[var_index++] = *src++;
+                        var_name[var_index] = 0;
+
+                        if (braces) {
+                                switch (*src) {
+                                case '}':
+                                        break;
+                                case '-':
+                                case '=':
+                                case '+':
+                                case '?':
+                                        operator = *src;
+                                        break;
+                                default:
+                                        err("unclosed ${\n");
+                                        return(0);
+                                }
+                                if (operator) { 
+                                        src++;
+                                        while (*src && (*src != '}')) {
+                                                alt_value[alt_index++] = *src++;
+                                        }
+                                        alt_value[alt_index] = 0;
+                                        if (*src != '}') {
+                                                err("unclosed ${\n");
+                                                return(0);
+                                        }
+                                }
+                                src++;
+                        }
+
+                        vp = lookup(var_name);
+                        if (vp->value != null)
+                                value = (operator == '+')? alt_value : vp->value;
+                        else if (operator == '?') {
+                                err(alt_value);
+                                return(0);
+                        } else if (alt_index && (operator != '+')) {
+                                value = alt_value;
+                                if (operator == '=')
+                                        setval(vp, value);
+                        } else
+                                continue;
+
+                        while (*value && (count < LINELIM)) {
+                                *dest++ = *value++;
+                                count++;
+                        }
+                } else {
+                        *dest++ = *src++;
+                        count++;
+                        ignore_once = 0;
+                }
+        }
+        *dest = '\0';
+        
         if (openpipe(pf) < 0)
                 return(0);
-        if ((i = vfork()) == -1) {
+        while ((i = vfork()) == -1 && errno == EAGAIN)
+                ;
+        if (i < 0) {
                 closepipe(pf);
-                err("try again");
+                err((char*)memory_exhausted);
                 return(0);
         }
         if (i != 0) {
+                waitpid(i, NULL, 0);
                 e.iop->argp->aword = ++cp;
                 close(pf[1]);
                 PUSHIO(afile, remap(pf[0]), (int(*)(struct ioarg *))((quoted)? qgravechar: gravechar));
                 return(1);
         }
-        *cp = 0;
         /* allow trapped signals */
-        for (i=0; i<=_NSIG; i++)
-                if (ourtrap[i] && signal(i, SIG_IGN) != SIG_IGN)
-                        signal(i, SIG_DFL);
+        /* XXX - Maybe this signal stuff should go as well? */
+        for (j=0; j<=_NSIG; j++)
+                if (ourtrap[j] && signal(j, SIG_IGN) != SIG_IGN)
+                        signal(j, SIG_DFL);
+        
         dup2(pf[1], 1);
         closepipe(pf);
-        flag['e'] = 0;
-        flag['v'] = 0;
-        flag['n'] = 0;
-        cp = strsave(e.iop->argp->aword, 0);
-        areanum = 1;
-        freehere(areanum);
-        freearea(areanum);      /* free old space */
-        e.oenv = NULL;
-        e.iop = (e.iobase = iostack) - 1;
-        unquote(cp);
-        interactive = 0;
-        PUSHIO(aword, cp, nlchar);
-        onecommand();
-        exit(1);
+
+        argument_list[0] = shellname;
+        argument_list[1] = "-c";
+        argument_list[2] = child_cmd;
+        argument_list[3] = 0;
+
+        prs(rexecve(argument_list[0], argument_list, makenv()));
+        _exit(1);
 }
 
+
 static char *
 unquote(as)
 register char *as;
@@ -4194,7 +4283,7 @@ static int my_getc( int ec)
                 return(c);
         }
         c = readc();
-        if (ec != '\'' && e.iop->task != XGRAVE) {
+        if ((ec != '\'') && (ec != '`') && (e.iop->task != XGRAVE)) {
                 if(c == '\\') {
                         c = readc();
                         if (c == '\n' && ec != '\"')
@@ -4457,7 +4546,7 @@ register struct ioarg *ap;
         }
 
 #ifdef CONFIG_FEATURE_COMMAND_EDITING
-        if (interactive) {
+        if (interactive && isatty(ap->afile)) {
             static char mycommand[BUFSIZ];
             static int position = 0, size = 0;
 
@@ -4568,7 +4657,7 @@ static void
 prn(u)
 unsigned u;
 {
-        prs(itoa(u, 0));
+        prs(itoa(u));
 }
 
 static void