Ok, sh.c should be working now. Many thanks to Larry Doolittle

for his timely help -- nearly all of the work in this patch is
his.
 -Erik


git-svn-id: svn://busybox.net/trunk/busybox@2022 69ca8d6d-28ef-0310-b511-8ec308f3f277

3 files changed, 249 insertions, 255 deletions

diff --git a/lash.c b/lash.c
index e1bdc875a..865f10b39 100644
--- a/lash.c
+++ b/lash.c
@@ -916,6 +916,7 @@ static int expand_arguments(char *command)
         expand_t expand_result;
         char *src, *dst, *var;
         int i=0, length, total_length=0, retval;
+        const char *out_of_space = "out of space during expansion"; 
 #endif
 
         /* get rid of the terminating \n */
@@ -931,7 +932,7 @@ static int expand_arguments(char *command)
         if (retval == WRDE_NOSPACE) {
                 /* Mem may have been allocated... */
                 wordfree (&expand_result);
-                error_msg("out of space during expansion");
+                error_msg(out_of_space);
                 return FALSE;
         }
         if (retval < 0) {
@@ -946,7 +947,7 @@ static int expand_arguments(char *command)
         while (i < expand_result.we_wordc && total_length < BUFSIZ) {
                 length=strlen(expand_result.we_wordv[i])+1;
                 if (BUFSIZ-total_length-length <= 0) {
-                        error_msg("out of space during expansion");
+                        error_msg(out_of_space);
                         return FALSE;
                 }
                 strcat(command+total_length, expand_result.we_wordv[i++]);
@@ -956,139 +957,136 @@ static int expand_arguments(char *command)
         wordfree (&expand_result);
 #else
 
-        /* Ok.  They don't have glibc and they don't have uClibc.  Chances are
-         * about 100% they don't have wordexp(), so instead, the best we can do is
-         * use glob, which is better then nothing, but certainly not perfect */
+        /* Ok.  They don't have a recent glibc and they don't have uClibc.  Chances
+         * are about 100% they don't have wordexp(). So instead the best we can do
+         * is use glob and then fixup environment variables and such ourselves.
+         * This is better then nothing, but certainly not perfect */
 
-        /* It turns out that glob is very stupid.  We have to feed it
-         * one word at a time since it can't cope with a full string. 
-         * Here we convert command (char*) into cmd (char**, one word 
-         * per string) */
+        /* It turns out that glob is very stupid.  We have to feed it one word at a
+         * time since it can't cope with a full string.  Here we convert command
+         * (char*) into cmd (char**, one word per string) */
         {
         
                 int flags = GLOB_NOCHECK|GLOB_BRACE|GLOB_TILDE;
                 char * tmpcmd;
                 /* We need a clean copy, so strsep can mess up the copy while
-                 * we write stuff into the original in a minute */
+                 * we write stuff into the original (in a minute) */
                 char * cmd = strdup(command);
+                *command = '\0';
                 for (tmpcmd = cmd; (tmpcmd = strsep(&cmd, " \t")) != NULL;) {
                         if (*tmpcmd == '\0')
                                 break;
                         retval = glob(tmpcmd, flags, NULL, &expand_result);
-                        /* We can't haveGLOB_APPEND on the first glob call,  
-                         * so put it there now */
-                        if (! (flags & GLOB_APPEND) ) 
-                                flags |= GLOB_APPEND;
-
                         if (retval == GLOB_NOSPACE) {
                                 /* Mem may have been allocated... */
                                 globfree (&expand_result);
-                                error_msg("out of space during expansion");
+                                error_msg(out_of_space);
                                 return FALSE;
-                        }
-                        if (retval != 0 && retval != GLOB_NOMATCH) {
-                                /* Some other error.  */
+                        } else if (retval != 0) {
+                                /* Some other error.  GLOB_NOMATCH shouldn't
+                                 * happen because of the GLOB_NOCHECK flag in 
+                                 * the glob call. */
                                 error_msg("syntax error");
                                 return FALSE;
-                        }
-
+                        } else {
                         /* Convert from char** (one word per string) to a simple char*,
                          * but don't overflow command which is BUFSIZ in length */
-                        if ( expand_result.gl_pathc > 1) {
-                                *command = '\0';
-                                while (i < expand_result.gl_pathc && total_length < BUFSIZ) {
+                                for (i=0; i < expand_result.gl_pathc; i++) {
                                         length=strlen(expand_result.gl_pathv[i])+1;
                                         if (BUFSIZ-total_length-length <= 0) {
-                                                error_msg("out of space during expansion");
+                                                error_msg(out_of_space);
                                                 return FALSE;
                                         }
-                                        strcat(command+total_length, expand_result.gl_pathv[i++]);
+                                        strcat(command+total_length, expand_result.gl_pathv[i]);
                                         strcat(command+total_length, " ");
                                         total_length+=length;
                                 }
+                                globfree (&expand_result);
                         }
                 }
-
                 free(cmd);
-                globfree (&expand_result);
+                trim(command);
         }
         
 #endif  
-        
-        /* FIXME -- this routine (which is only used when folks
-         * don't have a C library with wordexp) needs a bit of help
-         * to handle things like 'echo $PATH$0' */
-        
+
         /* Now do the shell variable substitutions which 
          * wordexp can't do for us, namely $? and $! */
         src = command;
         while((dst = strchr(src,'$')) != NULL){
-                /* Ok -- got a $ -- now clean up any trailing mess */
-                trim(dst);
-                if (!(var = getenv(dst + 1))) {
-                        switch(*(dst+1)) {
-                                case '?':
-                                        var = itoa(last_return_code);
-                                        break;
-                                case '!':
-                                        if (last_bg_pid==-1)
-                                                *(var)='\0';
-                                        else
-                                                var = itoa(last_bg_pid);
-                                        break;
+                printf("dollar '%s'\n", dst);
+                var = NULL;
+                switch(*(dst+1)) {
+                        case '?':
+                                var = itoa(last_return_code);
+                                break;
+                        case '!':
+                                if (last_bg_pid==-1)
+                                        *(var)='\0';
+                                else
+                                        var = itoa(last_bg_pid);
+                                break;
                                 /* Everything else like $$, $#, $[0-9], etc should all be
                                  * expanded by wordexp(), so we can in theory skip that stuff
                                  * here, but just to be on the safe side (i.e. since uClibc
                                  * wordexp doesn't do this stuff yet), lets leave it in for
                                  * now. */
-                                case '$':
-                                        var = itoa(getpid());
-                                        break;
-                                case '#':
-                                        var = itoa(argc-1);
-                                        break;
-                                case '0':case '1':case '2':case '3':case '4':
-                                case '5':case '6':case '7':case '8':case '9':
-                                        {
-                                                int index=*(dst + 1)-48;
-                                                if (index >= argc) {
-                                                        var='\0';
-                                                } else {
-                                                        var = argv[index];
-                                                }
+                        case '$':
+                                var = itoa(getpid());
+                                break;
+                        case '#':
+                                var = itoa(argc-1);
+                                break;
+                        case '0':case '1':case '2':case '3':case '4':
+                        case '5':case '6':case '7':case '8':case '9':
+                                {
+                                        int index=*(dst + 1)-48;
+                                        if (index >= argc) {
+                                                var='\0';
+                                        } else {
+                                                var = argv[index];
                                         }
-                                        break;
+                                }
+                                break;
 
-                        }
                 }
                 if (var) {
-                        int subst_len = strlen(var);
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst = dst;
-                        }
-                        src = (char*)xrealloc(src, strlen(src) - strlen(next_dst)+strlen(var)+1);
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst+subst_len, next_dst+1, subst_len); 
-                        /* Now copy in the new stuff */
-                        strncpy(dst, var, subst_len+1);
-                        src = dst;
-                        src++;
+                        /* a single character construction was found, and 
+                         * already handled in the case statement */
+                        src=dst+2;
                 } else {
+                        /* Looks like an environment variable */
+                        char delim_hold;
+                        src=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.");
+                        if (src == NULL) {
+                                src = dst+strlen(dst);
+                        }
+                        delim_hold=*src;
+                        *src='\0';  /* temporary */
+                        var = getenv(dst + 1);
+                        *src=delim_hold;
+                }
+                if (var == NULL) {
                         /* Seems we got an un-expandable variable.  So delete it. */
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst=dst+1+strlen(dst);
+                        var = "";
+                }
+                {
+                        int subst_len = strlen(var);
+                        int trail_len = strlen(src);
+                        if (dst+subst_len+trail_len >= command+BUFSIZ) {
+                                error_msg(out_of_space);
+                                return FALSE;
                         }
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst, next_dst,  next_dst-dst); 
+                        /* Move stuff to the end of the string to accommodate
+                         * filling the created gap with the new stuff */
+                        memmove(dst+subst_len, src, trail_len);
+                        *(dst+subst_len+trail_len)='\0';
+                        /* Now copy in the new stuff */
+                        memcpy(dst, var, subst_len);
+                        src = dst+subst_len;
                 }
         }
-
-
-
+        printf("expanded '%s'\n", command);
 
 #endif  
         return TRUE;
diff --git a/sh.c b/sh.c
index e1bdc875a..865f10b39 100644
--- a/sh.c
+++ b/sh.c
@@ -916,6 +916,7 @@ static int expand_arguments(char *command)
         expand_t expand_result;
         char *src, *dst, *var;
         int i=0, length, total_length=0, retval;
+        const char *out_of_space = "out of space during expansion"; 
 #endif
 
         /* get rid of the terminating \n */
@@ -931,7 +932,7 @@ static int expand_arguments(char *command)
         if (retval == WRDE_NOSPACE) {
                 /* Mem may have been allocated... */
                 wordfree (&expand_result);
-                error_msg("out of space during expansion");
+                error_msg(out_of_space);
                 return FALSE;
         }
         if (retval < 0) {
@@ -946,7 +947,7 @@ static int expand_arguments(char *command)
         while (i < expand_result.we_wordc && total_length < BUFSIZ) {
                 length=strlen(expand_result.we_wordv[i])+1;
                 if (BUFSIZ-total_length-length <= 0) {
-                        error_msg("out of space during expansion");
+                        error_msg(out_of_space);
                         return FALSE;
                 }
                 strcat(command+total_length, expand_result.we_wordv[i++]);
@@ -956,139 +957,136 @@ static int expand_arguments(char *command)
         wordfree (&expand_result);
 #else
 
-        /* Ok.  They don't have glibc and they don't have uClibc.  Chances are
-         * about 100% they don't have wordexp(), so instead, the best we can do is
-         * use glob, which is better then nothing, but certainly not perfect */
+        /* Ok.  They don't have a recent glibc and they don't have uClibc.  Chances
+         * are about 100% they don't have wordexp(). So instead the best we can do
+         * is use glob and then fixup environment variables and such ourselves.
+         * This is better then nothing, but certainly not perfect */
 
-        /* It turns out that glob is very stupid.  We have to feed it
-         * one word at a time since it can't cope with a full string. 
-         * Here we convert command (char*) into cmd (char**, one word 
-         * per string) */
+        /* It turns out that glob is very stupid.  We have to feed it one word at a
+         * time since it can't cope with a full string.  Here we convert command
+         * (char*) into cmd (char**, one word per string) */
         {
         
                 int flags = GLOB_NOCHECK|GLOB_BRACE|GLOB_TILDE;
                 char * tmpcmd;
                 /* We need a clean copy, so strsep can mess up the copy while
-                 * we write stuff into the original in a minute */
+                 * we write stuff into the original (in a minute) */
                 char * cmd = strdup(command);
+                *command = '\0';
                 for (tmpcmd = cmd; (tmpcmd = strsep(&cmd, " \t")) != NULL;) {
                         if (*tmpcmd == '\0')
                                 break;
                         retval = glob(tmpcmd, flags, NULL, &expand_result);
-                        /* We can't haveGLOB_APPEND on the first glob call,  
-                         * so put it there now */
-                        if (! (flags & GLOB_APPEND) ) 
-                                flags |= GLOB_APPEND;
-
                         if (retval == GLOB_NOSPACE) {
                                 /* Mem may have been allocated... */
                                 globfree (&expand_result);
-                                error_msg("out of space during expansion");
+                                error_msg(out_of_space);
                                 return FALSE;
-                        }
-                        if (retval != 0 && retval != GLOB_NOMATCH) {
-                                /* Some other error.  */
+                        } else if (retval != 0) {
+                                /* Some other error.  GLOB_NOMATCH shouldn't
+                                 * happen because of the GLOB_NOCHECK flag in 
+                                 * the glob call. */
                                 error_msg("syntax error");
                                 return FALSE;
-                        }
-
+                        } else {
                         /* Convert from char** (one word per string) to a simple char*,
                          * but don't overflow command which is BUFSIZ in length */
-                        if ( expand_result.gl_pathc > 1) {
-                                *command = '\0';
-                                while (i < expand_result.gl_pathc && total_length < BUFSIZ) {
+                                for (i=0; i < expand_result.gl_pathc; i++) {
                                         length=strlen(expand_result.gl_pathv[i])+1;
                                         if (BUFSIZ-total_length-length <= 0) {
-                                                error_msg("out of space during expansion");
+                                                error_msg(out_of_space);
                                                 return FALSE;
                                         }
-                                        strcat(command+total_length, expand_result.gl_pathv[i++]);
+                                        strcat(command+total_length, expand_result.gl_pathv[i]);
                                         strcat(command+total_length, " ");
                                         total_length+=length;
                                 }
+                                globfree (&expand_result);
                         }
                 }
-
                 free(cmd);
-                globfree (&expand_result);
+                trim(command);
         }
         
 #endif  
-        
-        /* FIXME -- this routine (which is only used when folks
-         * don't have a C library with wordexp) needs a bit of help
-         * to handle things like 'echo $PATH$0' */
-        
+
         /* Now do the shell variable substitutions which 
          * wordexp can't do for us, namely $? and $! */
         src = command;
         while((dst = strchr(src,'$')) != NULL){
-                /* Ok -- got a $ -- now clean up any trailing mess */
-                trim(dst);
-                if (!(var = getenv(dst + 1))) {
-                        switch(*(dst+1)) {
-                                case '?':
-                                        var = itoa(last_return_code);
-                                        break;
-                                case '!':
-                                        if (last_bg_pid==-1)
-                                                *(var)='\0';
-                                        else
-                                                var = itoa(last_bg_pid);
-                                        break;
+                printf("dollar '%s'\n", dst);
+                var = NULL;
+                switch(*(dst+1)) {
+                        case '?':
+                                var = itoa(last_return_code);
+                                break;
+                        case '!':
+                                if (last_bg_pid==-1)
+                                        *(var)='\0';
+                                else
+                                        var = itoa(last_bg_pid);
+                                break;
                                 /* Everything else like $$, $#, $[0-9], etc should all be
                                  * expanded by wordexp(), so we can in theory skip that stuff
                                  * here, but just to be on the safe side (i.e. since uClibc
                                  * wordexp doesn't do this stuff yet), lets leave it in for
                                  * now. */
-                                case '$':
-                                        var = itoa(getpid());
-                                        break;
-                                case '#':
-                                        var = itoa(argc-1);
-                                        break;
-                                case '0':case '1':case '2':case '3':case '4':
-                                case '5':case '6':case '7':case '8':case '9':
-                                        {
-                                                int index=*(dst + 1)-48;
-                                                if (index >= argc) {
-                                                        var='\0';
-                                                } else {
-                                                        var = argv[index];
-                                                }
+                        case '$':
+                                var = itoa(getpid());
+                                break;
+                        case '#':
+                                var = itoa(argc-1);
+                                break;
+                        case '0':case '1':case '2':case '3':case '4':
+                        case '5':case '6':case '7':case '8':case '9':
+                                {
+                                        int index=*(dst + 1)-48;
+                                        if (index >= argc) {
+                                                var='\0';
+                                        } else {
+                                                var = argv[index];
                                         }
-                                        break;
+                                }
+                                break;
 
-                        }
                 }
                 if (var) {
-                        int subst_len = strlen(var);
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst = dst;
-                        }
-                        src = (char*)xrealloc(src, strlen(src) - strlen(next_dst)+strlen(var)+1);
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst+subst_len, next_dst+1, subst_len); 
-                        /* Now copy in the new stuff */
-                        strncpy(dst, var, subst_len+1);
-                        src = dst;
-                        src++;
+                        /* a single character construction was found, and 
+                         * already handled in the case statement */
+                        src=dst+2;
                 } else {
+                        /* Looks like an environment variable */
+                        char delim_hold;
+                        src=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.");
+                        if (src == NULL) {
+                                src = dst+strlen(dst);
+                        }
+                        delim_hold=*src;
+                        *src='\0';  /* temporary */
+                        var = getenv(dst + 1);
+                        *src=delim_hold;
+                }
+                if (var == NULL) {
                         /* Seems we got an un-expandable variable.  So delete it. */
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst=dst+1+strlen(dst);
+                        var = "";
+                }
+                {
+                        int subst_len = strlen(var);
+                        int trail_len = strlen(src);
+                        if (dst+subst_len+trail_len >= command+BUFSIZ) {
+                                error_msg(out_of_space);
+                                return FALSE;
                         }
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst, next_dst,  next_dst-dst); 
+                        /* Move stuff to the end of the string to accommodate
+                         * filling the created gap with the new stuff */
+                        memmove(dst+subst_len, src, trail_len);
+                        *(dst+subst_len+trail_len)='\0';
+                        /* Now copy in the new stuff */
+                        memcpy(dst, var, subst_len);
+                        src = dst+subst_len;
                 }
         }
-
-
-
+        printf("expanded '%s'\n", command);
 
 #endif  
         return TRUE;
diff --git a/shell/lash.c b/shell/lash.c
index e1bdc875a..865f10b39 100644
--- a/shell/lash.c
+++ b/shell/lash.c
@@ -916,6 +916,7 @@ static int expand_arguments(char *command)
         expand_t expand_result;
         char *src, *dst, *var;
         int i=0, length, total_length=0, retval;
+        const char *out_of_space = "out of space during expansion"; 
 #endif
 
         /* get rid of the terminating \n */
@@ -931,7 +932,7 @@ static int expand_arguments(char *command)
         if (retval == WRDE_NOSPACE) {
                 /* Mem may have been allocated... */
                 wordfree (&expand_result);
-                error_msg("out of space during expansion");
+                error_msg(out_of_space);
                 return FALSE;
         }
         if (retval < 0) {
@@ -946,7 +947,7 @@ static int expand_arguments(char *command)
         while (i < expand_result.we_wordc && total_length < BUFSIZ) {
                 length=strlen(expand_result.we_wordv[i])+1;
                 if (BUFSIZ-total_length-length <= 0) {
-                        error_msg("out of space during expansion");
+                        error_msg(out_of_space);
                         return FALSE;
                 }
                 strcat(command+total_length, expand_result.we_wordv[i++]);
@@ -956,139 +957,136 @@ static int expand_arguments(char *command)
         wordfree (&expand_result);
 #else
 
-        /* Ok.  They don't have glibc and they don't have uClibc.  Chances are
-         * about 100% they don't have wordexp(), so instead, the best we can do is
-         * use glob, which is better then nothing, but certainly not perfect */
+        /* Ok.  They don't have a recent glibc and they don't have uClibc.  Chances
+         * are about 100% they don't have wordexp(). So instead the best we can do
+         * is use glob and then fixup environment variables and such ourselves.
+         * This is better then nothing, but certainly not perfect */
 
-        /* It turns out that glob is very stupid.  We have to feed it
-         * one word at a time since it can't cope with a full string. 
-         * Here we convert command (char*) into cmd (char**, one word 
-         * per string) */
+        /* It turns out that glob is very stupid.  We have to feed it one word at a
+         * time since it can't cope with a full string.  Here we convert command
+         * (char*) into cmd (char**, one word per string) */
         {
         
                 int flags = GLOB_NOCHECK|GLOB_BRACE|GLOB_TILDE;
                 char * tmpcmd;
                 /* We need a clean copy, so strsep can mess up the copy while
-                 * we write stuff into the original in a minute */
+                 * we write stuff into the original (in a minute) */
                 char * cmd = strdup(command);
+                *command = '\0';
                 for (tmpcmd = cmd; (tmpcmd = strsep(&cmd, " \t")) != NULL;) {
                         if (*tmpcmd == '\0')
                                 break;
                         retval = glob(tmpcmd, flags, NULL, &expand_result);
-                        /* We can't haveGLOB_APPEND on the first glob call,  
-                         * so put it there now */
-                        if (! (flags & GLOB_APPEND) ) 
-                                flags |= GLOB_APPEND;
-
                         if (retval == GLOB_NOSPACE) {
                                 /* Mem may have been allocated... */
                                 globfree (&expand_result);
-                                error_msg("out of space during expansion");
+                                error_msg(out_of_space);
                                 return FALSE;
-                        }
-                        if (retval != 0 && retval != GLOB_NOMATCH) {
-                                /* Some other error.  */
+                        } else if (retval != 0) {
+                                /* Some other error.  GLOB_NOMATCH shouldn't
+                                 * happen because of the GLOB_NOCHECK flag in 
+                                 * the glob call. */
                                 error_msg("syntax error");
                                 return FALSE;
-                        }
-
+                        } else {
                         /* Convert from char** (one word per string) to a simple char*,
                          * but don't overflow command which is BUFSIZ in length */
-                        if ( expand_result.gl_pathc > 1) {
-                                *command = '\0';
-                                while (i < expand_result.gl_pathc && total_length < BUFSIZ) {
+                                for (i=0; i < expand_result.gl_pathc; i++) {
                                         length=strlen(expand_result.gl_pathv[i])+1;
                                         if (BUFSIZ-total_length-length <= 0) {
-                                                error_msg("out of space during expansion");
+                                                error_msg(out_of_space);
                                                 return FALSE;
                                         }
-                                        strcat(command+total_length, expand_result.gl_pathv[i++]);
+                                        strcat(command+total_length, expand_result.gl_pathv[i]);
                                         strcat(command+total_length, " ");
                                         total_length+=length;
                                 }
+                                globfree (&expand_result);
                         }
                 }
-
                 free(cmd);
-                globfree (&expand_result);
+                trim(command);
         }
         
 #endif  
-        
-        /* FIXME -- this routine (which is only used when folks
-         * don't have a C library with wordexp) needs a bit of help
-         * to handle things like 'echo $PATH$0' */
-        
+
         /* Now do the shell variable substitutions which 
          * wordexp can't do for us, namely $? and $! */
         src = command;
         while((dst = strchr(src,'$')) != NULL){
-                /* Ok -- got a $ -- now clean up any trailing mess */
-                trim(dst);
-                if (!(var = getenv(dst + 1))) {
-                        switch(*(dst+1)) {
-                                case '?':
-                                        var = itoa(last_return_code);
-                                        break;
-                                case '!':
-                                        if (last_bg_pid==-1)
-                                                *(var)='\0';
-                                        else
-                                                var = itoa(last_bg_pid);
-                                        break;
+                printf("dollar '%s'\n", dst);
+                var = NULL;
+                switch(*(dst+1)) {
+                        case '?':
+                                var = itoa(last_return_code);
+                                break;
+                        case '!':
+                                if (last_bg_pid==-1)
+                                        *(var)='\0';
+                                else
+                                        var = itoa(last_bg_pid);
+                                break;
                                 /* Everything else like $$, $#, $[0-9], etc should all be
                                  * expanded by wordexp(), so we can in theory skip that stuff
                                  * here, but just to be on the safe side (i.e. since uClibc
                                  * wordexp doesn't do this stuff yet), lets leave it in for
                                  * now. */
-                                case '$':
-                                        var = itoa(getpid());
-                                        break;
-                                case '#':
-                                        var = itoa(argc-1);
-                                        break;
-                                case '0':case '1':case '2':case '3':case '4':
-                                case '5':case '6':case '7':case '8':case '9':
-                                        {
-                                                int index=*(dst + 1)-48;
-                                                if (index >= argc) {
-                                                        var='\0';
-                                                } else {
-                                                        var = argv[index];
-                                                }
+                        case '$':
+                                var = itoa(getpid());
+                                break;
+                        case '#':
+                                var = itoa(argc-1);
+                                break;
+                        case '0':case '1':case '2':case '3':case '4':
+                        case '5':case '6':case '7':case '8':case '9':
+                                {
+                                        int index=*(dst + 1)-48;
+                                        if (index >= argc) {
+                                                var='\0';
+                                        } else {
+                                                var = argv[index];
                                         }
-                                        break;
+                                }
+                                break;
 
-                        }
                 }
                 if (var) {
-                        int subst_len = strlen(var);
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst = dst;
-                        }
-                        src = (char*)xrealloc(src, strlen(src) - strlen(next_dst)+strlen(var)+1);
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst+subst_len, next_dst+1, subst_len); 
-                        /* Now copy in the new stuff */
-                        strncpy(dst, var, subst_len+1);
-                        src = dst;
-                        src++;
+                        /* a single character construction was found, and 
+                         * already handled in the case statement */
+                        src=dst+2;
                 } else {
+                        /* Looks like an environment variable */
+                        char delim_hold;
+                        src=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.");
+                        if (src == NULL) {
+                                src = dst+strlen(dst);
+                        }
+                        delim_hold=*src;
+                        *src='\0';  /* temporary */
+                        var = getenv(dst + 1);
+                        *src=delim_hold;
+                }
+                if (var == NULL) {
                         /* Seems we got an un-expandable variable.  So delete it. */
-                        char *next_dst;
-                        if ((next_dst=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.")) == NULL) {
-                                next_dst=dst+1+strlen(dst);
+                        var = "";
+                }
+                {
+                        int subst_len = strlen(var);
+                        int trail_len = strlen(src);
+                        if (dst+subst_len+trail_len >= command+BUFSIZ) {
+                                error_msg(out_of_space);
+                                return FALSE;
                         }
-                        /* Move stuff to the end of the string to accommodate filling 
-                         * the created gap with the new stuff */
-                        memmove(dst, next_dst,  next_dst-dst); 
+                        /* Move stuff to the end of the string to accommodate
+                         * filling the created gap with the new stuff */
+                        memmove(dst+subst_len, src, trail_len);
+                        *(dst+subst_len+trail_len)='\0';
+                        /* Now copy in the new stuff */
+                        memcpy(dst, var, subst_len);
+                        src = dst+subst_len;
                 }
         }
-
-
-
+        printf("expanded '%s'\n", command);
 
 #endif  
         return TRUE;