Ok, sh.c should be working now. Many thanks to Larry Doolittle
authorEric Andersen <andersen@codepoet.org>
Fri, 9 Mar 2001 19:21:37 +0000 (19:21 -0000)
committerEric Andersen <andersen@codepoet.org>
Fri, 9 Mar 2001 19:21:37 +0000 (19:21 -0000)
for his timely help -- nearly all of the work in this patch is
his.
 -Erik

lash.c
sh.c
shell/lash.c

diff --git a/lash.c b/lash.c
index e1bdc875a5f2c64cc2f78c68701fbcb7eb059003..865f10b394236ecfaca2b205e85c80a3882d3db0 100644 (file)
--- 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 e1bdc875a5f2c64cc2f78c68701fbcb7eb059003..865f10b394236ecfaca2b205e85c80a3882d3db0 100644 (file)
--- 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;
index e1bdc875a5f2c64cc2f78c68701fbcb7eb059003..865f10b394236ecfaca2b205e85c80a3882d3db0 100644 (file)
@@ -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;