From 707936efe324436a32d2924ef9eb7ee9641bdc16 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 29 Nov 2019 23:55:13 +0100
Subject: [PATCH] enable setting a variable from an input file using the
 existing i/o redirection

---
 src/frontend/com_set.c | 61 ++++++++++++++++++++++++++++++++++++++++++
 src/frontend/streams.c | 12 ++++++---
 2 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/src/frontend/com_set.c b/src/frontend/com_set.c
index 62bfa7ca9..688c22feb 100644
--- a/src/frontend/com_set.c
+++ b/src/frontend/com_set.c
@@ -6,6 +6,8 @@
 #include "variable.h"
 #include "com_set.h"
 
+wordlist* readifile(wordlist*);
+
 
 /* The set command. Syntax is set [opt ...] [opt = val ...]. Val may
  * be a string, an int, a float, or a list of the form (elt1 elt2
@@ -19,6 +21,12 @@ com_set(wordlist *wl)
         cp_vprint();
         return;
     }
+
+    /* special case input redirection*/
+    wordlist *ww = wl->wl_next;
+    if (ww && eq(ww->wl_word, "<"))
+        wl = readifile(wl);
+
     vars = cp_setparse(wl);
 
     /* This is sort of a hassle... */
@@ -54,3 +62,56 @@ com_set(wordlist *wl)
         tfree(oldvar);
     }
 }
+
+/* read a file from cp_in, add the tokens to a wordlist and
+   create an input for a string list like set ccc = ( 3 5 7 ).
+   Comment lines in input file (starting with '*') are ignored. */
+wordlist*
+readifile(wordlist* win)
+{
+    /* max file size */
+    char intoken[4096];
+    /* save start address */
+    wordlist* tw = win;
+    char *tmpstr;
+
+    /* delete wordlist from '<' on */
+    wl_free(win->wl_next);
+    wl_append_word(&win, &win, copy("="));
+    wl_append_word(&win, &win, copy("("));
+    /* read a line. If it starts with '*', ignore it */
+    while (fgets(intoken, 4096, cp_in) != NULL) {
+        if (intoken[0] == '*')
+            continue;
+        char* delstr;
+        char* instr = delstr = copy(intoken);
+        /* get all tokens, ignoring '\n' 
+           and add to string list */
+        while ((tmpstr = gettok(&instr)) != NULL) {
+            wl_append_word(&win, &win, tmpstr);
+        }
+        tfree(delstr);
+    }
+    wl_append_word(&win, &win, copy(")"));
+    /* close and reset cp_in 
+    (was opened in streams.c:84) */
+    cp_ioreset();
+    return tw;
+#if 0
+    size_t retval = fread(intoken, 1, 4096, cp_in);
+    intoken[retval] = '\0';
+    char* delstr;
+    char* instr = delstr = copy(intoken);
+    /* get all tokens, ignoring '\n' 
+    and add to string list */
+    while ((tmpstr = gettok(&instr)) != NULL) {
+        wl_append_word(&win, &win, tmpstr);
+    }
+    tfree(delstr);
+    wl_append_word(&win, &win, copy(")"));
+    /* close and reset cp_in 
+    (was opened in streams.c:84) */
+    cp_ioreset();
+    return tw;
+#endif
+}
diff --git a/src/frontend/streams.c b/src/frontend/streams.c
index 8906fd33c..8558220b1 100644
--- a/src/frontend/streams.c
+++ b/src/frontend/streams.c
@@ -82,16 +82,20 @@ cp_redirect(wordlist *wl)
 #endif
 
             fp = fopen(fname, "r");
-            tfree(fname);
-
             if (!fp) {
                 perror(fname);
+                tfree(fname);
                 goto error;
             }
-
+			
+			tfree(fname);
             cp_in = fp;
 
-            wl_delete_slice(beg, w);
+            /* special case for set command:
+               keep i/o information (handled in com_set.c)  */
+            wordlist* bw = beg->wl_prev->wl_prev;
+            if (!(bw && cieq(bw->wl_word, "set")))
+                wl_delete_slice(beg, w);
 
         } else if (*w->wl_word == cp_gt) {