From 3d92b273bbbff3200478924f76455659a8638274 Mon Sep 17 00:00:00 2001
From: Jakob Kaivo <jkk@ung.org>
Date: Mon, 28 Mar 2022 11:10:32 -0400
Subject: extract reading the next command into a function

---
 menudriver.c | 112 ++++++++++++++++++++++-------------------------------------
 1 file changed, 42 insertions(+), 70 deletions(-)

diff --git a/menudriver.c b/menudriver.c
index 10e1c26..7447e73 100644
--- a/menudriver.c
+++ b/menudriver.c
@@ -9,6 +9,7 @@
  * Revised to C11 standard and made 64bit compatible, January 2020        *
  *------------------------------------------------------------------------*/
 
+#include <ctype.h>
 #include <errno.h>
 #include <limits.h>
 #include <signal.h>
@@ -39,13 +40,35 @@ int fastback = 0;
 #endif
 
 void callshell(char[]);
-void clrscr(void);
 void menudrive(const char *, const char *, char *);
 void pushlast(char *);
 void poplast(char *);
 void settings(const char *, const char *, int);
 int subdir(void);
 
+static void clear_screen(void)
+{
+  system("tput clear");
+}
+
+static int read_next(size_t n, char buf[static n])
+{
+  int c;
+  do {
+    c = getchar();
+  } while (c == ' ' || c == '\t');
+  ungetc(c, stdin);
+
+  if (fgets(buf, n, stdin) == NULL) {
+    return 0;
+  }
+
+  for (char *end = strchr(buf, '\n'); isspace(*end); end--) {
+    *end = '\0';
+  }
+  return 1;
+}
+
 static void wait_for_return(void)
 {
   printf("[Hit return to continue]");
@@ -86,7 +109,7 @@ static void view_file(const char *viewer, const char *filename)
     return;
   }
 
-  clrscr();
+  clear_screen();
 
   char cmd[PATH_MAX];
 
@@ -156,8 +179,6 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
 {
   char next[40] = "", last[40] = ".";
 
-  char *np;
-  int c;
   int bad = 0;
 
   if (chdir(dir) == -1) {
@@ -168,7 +189,7 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
   struct stat st;
   while (stat("contents", &st) == 0) {
     if (next[0] == '\0' || bad) {
-      clrscr();
+      clear_screen();
 
       /* invalid selection notified here, after clearing screen */
       if (bad) {
@@ -182,29 +203,9 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
 
       view_menu(menuviewer, "contents");
       printf("::please type selection number (or return to exit):");
-
-      /* read remainder of line into next, less leading white space */
-      np = next;
-      c = getchar();
-      while (c == ' ' || c == '\t') {
-	c = getchar();
-      }
-
-      while (c != '\n' && c != EOF) {
-	*np++ = c, c = getchar();
-      }
-
-      if (c == EOF) {
-	exit(0);
+      if (!read_next(sizeof(next), next)) {
+        exit(0);
       }
-
-      /* remove trailing white space */
-      if (next[0] != '!') {
-	while (np[-1] == ' ' || np[-1] == '\t') {
-	  np--;
-        }
-      }
-      *np = '\0';
     }
 
     if (next[0] == '\0') {
@@ -238,7 +239,7 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
           exit(1);
         }
 
-	if (chdir(next) == -1 || stat("contents", &st)) {
+	if (chdir(next) == -1 || stat("contents", &st) == -1) {
 	  bad = 1;
           chdir(hold);
 	} else {
@@ -249,38 +250,16 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
 
       } else if (S_ISREG(st.st_mode)) {
         view_file(viewer, next);
+        strcpy(last, next);
 
 	if (fastback) {
-	  strcpy(last, next);
 	  next[0] = '\0';
 
 	} else {
 	  printf("::next selection (or return to go back to menu, or q to quit):");
-	  /* read remainder of line into next, less leading white space */
-	  strcpy(last, next);
-	  np = next;
-
-	  c = getchar();
-	  while (c == ' ' || c == '\t') {
-	    c = getchar();
-          }
-
-	  while (c != '\n' && c != EOF) {
-	    *np++ = c;
-            c = getchar();
-          }
-
-	  if (c == EOF) {
-	    exit(0);
-          }
-
-	  /* remove trailing white space */
-	  if (next[0] != '!') {
-	    while (np[-1] == ' ' || np[-1] == '\t') {
-	      np--;
-            }
+          if (!read_next(sizeof(next), next)) {
+            exit(0);
           }
-	  *np = '\0';
 	}
       }
 
@@ -324,7 +303,7 @@ void menudrive(const char *menuviewer, const char *viewer, char *dir)
 
 /* possibly a bug - can retreat above original dir, if parent contains a
    "contents" file - difficult to detect this in a general way, however */
-/* pathnames banned because 
+/* pathnames banned because
    (i) upward pathname will not return correctly if a directory (see above)
    (ii) direct selection of a grandchild directory leads to
         (a) returns via child, instead of directly
@@ -385,7 +364,8 @@ prompt at bottom of a manual section before getting back to the contents\n\
 page - to cure this set RETURNTOMENU=YES;\n\n");
 */
 
-char lastvec[100], *lastp = lastvec + 1;
+char lastvec[100];
+char *lastp = lastvec + 1;
 int giveup = 0;
 
 int subdir(void)
@@ -395,17 +375,15 @@ int subdir(void)
 
 void pushlast(char *last)
 {
-  int n = strlen(last);
-  if (last[0] == '.') {
-    /* pathological cases */
-    if (last[1] == '\0') {
-      return;
-    } else if (last[1] == '.' && last[2] == '\0') {
-      poplast(last);
-      return;
-    }
+  if (!strcmp(last, ".")) {
+    return;
+  } else if (!strcmp(last, "..")) {
+    poplast(last);
+    return;
   }
 
+  size_t n = strlen(last);
+
   if (lastp + n > lastvec + 100) {	/* overflow */
     giveup = 1;
     return;
@@ -431,9 +409,3 @@ void poplast(char *last)
 
   strcpy(last, ++lastp);
 }
-
-/* to clear screen */
-void clrscr(void)
-{
-  system("tput clear");
-}
-- 
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