Add 'get-environment-variable', in a fashion:

(define curdir(get-environment-variable CURDIR))
(insert curdir)

Should now print the value of the environment variable CURDIR's value,
or error if it is not set.

diff --git a/usr.bin/mg/interpreter.c b/usr.bin/mg/interpreter.c
index 91ea9e8..47d3a25 100644 (file)
--- a/usr.bin/mg/interpreter.c
+++ b/usr.bin/mg/interpreter.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: interpreter.c,v 1.19 2021/03/26 08:27:49 lum Exp $   */
+/*      $OpenBSD: interpreter.c,v 1.20 2021/03/26 12:31:37 lum Exp $   */
 /*
  * This file is in the public domain.
  *
@@ -475,8 +475,8 @@ static int
 foundvar(char *defstr)
 {
        struct varentry *vt, *v1 = NULL;
-       const char       t[2] = "t";
        char            *p, *vnamep, *vendp = NULL, *valp;
+       char             tmpbuf[BUFSIZE];
        int              spc;
 
        /* vars names can't start with these. */
@@ -496,7 +496,6 @@ foundvar(char *defstr)
 
        /*
         * Check list name is not an existing function.
-        * Although could this be allowed? Shouldn't context dictate?
         */
        if (name_function(vnamep) != NULL)
                return(dobeep_msgs("Variable/function name clash:", vnamep));
@@ -504,9 +503,36 @@ foundvar(char *defstr)
        p = ++vendp;
        p = skipwhite(p);
 
-       if ((*p == 'l') && (*(p + 1) == 'i') && (*(p + 2) == 's')) {
-               p = strstr(p, t);       /* find 't' in 'list'.  */
-               valp = skipwhite(++p);  /* find first value     */
+       /*
+        * Now what have we found? A keyword (e.g list)? A value?
+        * We only deal with values and a couple of keywords at moment.
+        */
+       if (strncmp(p, "list ", 5) == 0) {
+               p = strstr(p, " ");     /* find ' ' after 'list'.  */
+               valp = skipwhite(p);    /* find first value     */
+       } else if (strncmp(p, "get-environment-variable ", 25) == 0) {
+               const char      *t;
+               char            *tmp;
+               const char      *q = "\"";
+
+               p = strstr(p, " ");     /* find ' ' after keyword.  */
+               t = skipwhite(p);    /* find first value     */
+
+               if (t[0] == *q || t[strlen(t) - 1] == *q)
+                       return (dobeep_msgs("Please remove '\"' around:",
+                           t));
+               if ((tmp = getenv(t)) == NULL || *tmp == '\0')
+                       return(dobeep_msgs("Envar not found:", t));
+               /* envar is returned without "" around the string */
+               tmpbuf[0] = '\0';
+               if (strlcat(tmpbuf, q, sizeof(tmpbuf)) >= sizeof(tmpbuf))
+                       return (dobeep_msg("strlcat error"));
+               if (strlcat(tmpbuf, tmp, sizeof(tmpbuf)) >= sizeof(tmpbuf))
+                       return (dobeep_msg("strlcat error"));
+               if (strlcat(tmpbuf, q, sizeof(tmpbuf)) >= sizeof(tmpbuf))
+                       return (dobeep_msg("strlcat error"));
+               
+               valp = tmpbuf;
        } else
                valp = p;
        /*