Imported Upstream version 93u+upstream

1 files changed, 255 insertions, 0 deletions

diff --git a/src/cmd/ksh93/sh/env.c b/src/cmd/ksh93/sh/env.c
new file mode 100644
index 0000000..717c8b8
--- /dev/null
+++ b/src/cmd/ksh93/sh/env.c
@@ -0,0 +1,255 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1982-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                  David Korn <dgk@research.att.com>                   *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+
+#include	<ast.h>
+#include	<cdt.h>
+
+#define	env_change()		(++ast.env_serial)
+
+typedef struct _venv_ Evar_t;
+struct _venv_
+{
+	union
+	{
+		Evar_t		*next;
+		char		*ptr;
+	}	un;
+	Dtlink_t	link;
+	int		index;
+};
+
+typedef  struct _env_
+{
+	Dt_t	*dt;
+	Evar_t	*freelist;
+	char	**env;
+	int	count;
+	int	extra;
+	int	max;
+	int	flags;
+} Env_t;
+
+#define _BLD_env	1
+#include	<env.h>
+
+#define ENV_VALID	2		/* set if env is valid */
+#define ENV_PMALLOC	1		/* set if Evar_t->un.ptr  *s malloced */
+#define ENV_VMALLOC	2		/* set of Evar_t was malloced */
+#define ENV_BITS	3
+
+/*
+ * Compares the name portion of name=... only.
+ */
+static int compare(Dt_t *dt, Void_t* key1, Void_t* key2, Dtdisc_t* disc)
+{
+	register int c,d;
+	const unsigned char *s1=(unsigned const char*)key1;
+	const unsigned char *s2=(unsigned const char*)key2; 
+	while((c= *s1++) && c!='=' && c==*s2) 
+		s2++;
+	if(c=='=')
+		c = 0;
+	if((d=*s2)=='=')
+		d = 0;
+	return(c-d);
+}
+
+static Dtdisc_t env_disc =
+{
+	0, -1,
+	sizeof(char*),
+	0,
+	0,
+	compare
+};
+
+/*
+ *  return a pointer to the environment in sorted order
+ *  NULL is returned if there if there is nospace
+ */
+char **env_get(Env_t* ep)
+{
+	register Evar_t *vp;
+	register int n=ep->extra;
+	if(ep->flags&ENV_VALID)
+		return(ep->env+n);
+	if(ep->count > ep->max)
+	{
+		if(ep->flags&ENV_MALLOCED)
+			free((void*)ep->env);
+		if(!(ep->env = (char**)malloc(sizeof(char*)*(ep->count+1))))
+			return(0);
+		ep->flags |= ENV_MALLOCED;
+		ep->max = ep->count;
+	}
+	for(vp=(Evar_t*)dtfirst(ep->dt);vp; vp=(Evar_t*)dtnext(ep->dt,vp))
+	{
+		vp->index = (n<<ENV_BITS) | (vp->index&((1<<ENV_BITS)-1));
+		ep->env[n++] = vp->un.ptr;
+	}
+	ep->env[n] = 0;
+	ep->flags |= ENV_VALID;
+	environ = ep->env+ep->extra;
+	return(ep->env+ep->extra);
+}
+
+/*
+ *  add name=value pair given by <str> to <ep>
+ *  if malloced is set, the variable will be freed when reassigned
+ *  The environment list may become invalidated
+ *  Returns 1 for success, 0 for failure
+ */
+int env_add(Env_t *ep, const char *str, int flags)
+{
+	Evar_t *vp = (Evar_t*)dtmatch(ep->dt,(void*)str);
+	if(vp && strcmp(str,vp->un.ptr)==0)
+		return(1);
+	if(flags&ENV_STRDUP)
+		str = strdup(str);
+	if(vp)
+	{
+		if(vp->index&ENV_PMALLOC)
+			free((void*)vp->un.ptr);
+		vp->un.ptr = (char*)str;
+		if(ep->env && (ep->flags&ENV_VALID))
+			ep->env[vp->index>>ENV_BITS] = vp->un.ptr;
+	}
+	else
+	{
+		ep->flags &= ~ENV_VALID;
+		if(vp = ep->freelist)
+			ep->freelist = vp->un.next;
+		else if(vp = newof((Evar_t*)0,Evar_t,2,0))
+		{
+			vp->index = ENV_VMALLOC;
+			ep->freelist = (vp+1);
+			ep->freelist->un.next = 0;
+		}
+		else
+			return(0);
+		vp->un.ptr = (void*)str;
+		if(!(vp=dtinsert(ep->dt,vp)))
+			return(0);
+		ep->count++;
+	}
+	if(flags)
+		vp->index |= ENV_PMALLOC;
+	else
+		vp->index &= ~ENV_PMALLOC;
+	env_change();
+	return(1);
+}
+
+/*
+ *  delete name  from <ep>
+ *  The environment list may become invalidated
+ *  Returns 1 for success, 0 for if name is not present 
+ */
+int env_delete(Env_t *ep, const char *str)
+{
+	Evar_t *vp = (Evar_t*)dtmatch(ep->dt,(void*)str);
+	if(!vp)
+		return(0);
+	ep->flags &= ~ENV_VALID;
+	if(vp->index&ENV_PMALLOC)
+		free((void*)vp->un.ptr);
+	dtdelete(ep->dt,vp);
+	vp->un.next = ep->freelist;
+	ep->freelist = vp;
+	env_change();
+	return(1);
+}
+
+/*
+ * open up a structure to support environment variables
+ * initialize with environment give by <envp>
+ * If <extra> > 0, <extra> slots will be left at beginning of
+ *    environment list when env_get() is involed.
+ * If <extra>==ENV_USABLE, then the original environ can be
+ *   used and returned.  Otherwise, a new one will be returned
+ */
+Env_t *env_open(char **envp, int extra)
+{
+	char **env;
+	Env_t *ep;
+	Evar_t *vp;
+	int n=2;
+	if(!(ep = newof((Env_t*)0,Env_t,1,0)))
+		return(0);
+	if(!(ep->dt = dtopen(&env_disc,Dtoset)))
+		return(0);
+	if(env=envp)
+	{
+		while(*env++);
+		n = (env+2)-envp;
+	}
+	if(extra==ENV_STABLE)
+	{
+		ep->env = envp;
+		ep->max = n-1;
+	}
+	else
+		ep->count = ep->extra = extra;
+	ep->freelist = vp = newof((Evar_t*)0,Evar_t,n,0);
+	vp->index = ENV_VMALLOC;
+	while(--n>0)
+	{
+		vp->un.next = (vp+1);
+		vp++;
+	}
+	vp->un.next = 0;
+	if(env)
+	{
+		for(env=envp; *env; env++)
+			env_add(ep,*env,0);
+	}
+	return(ep);
+}
+
+/*
+ * close <ep> and free up all space used by it
+ */
+void env_close(Env_t *ep)
+{
+	Evar_t *vp, *vpnext,*top;
+	if(ep->env && (ep->flags&ENV_MALLOCED))
+		free((void*)ep->env);
+	for(vp=(Evar_t*)dtfirst(ep->dt);vp; vp=vpnext)
+	{
+		vpnext = (Evar_t*)dtnext(ep->dt,vp);
+		env_delete(ep,vp->un.ptr);
+	}
+	for(top=0,vp = ep->freelist; vp; vp = vpnext)
+	{
+		vpnext = vp->un.next;
+		if(vp->index&ENV_VMALLOC)
+		{
+			vp->un.next = top;
+			top = vp;
+		}
+	}
+	for(vp=top; vp; vp = vpnext)
+	{
+		vpnext = vp->un.next;
+		free((void*)vp);
+	}
+	dtclose(ep->dt);
+}