Factor out draw_str() and friends.

2 files changed, 150 insertions, 5 deletions

diff --git a/lib/lib.h b/lib/lib.h
index 750e1240..b0d7f360 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -3,6 +3,16 @@
  * Copyright 2006 Rob Landley <rob@landley.net>
  */
 
+struct ptr_len {
+  void *ptr;
+  long len;
+};
+
+struct str_len {
+  char *str;
+  long len;
+};
+
 // llist.c
 
 // All these list types can be handled by the same code because first element
@@ -24,11 +34,6 @@ struct double_list {
   char *data;
 };
 
-struct ptr_len {
-  void *ptr;
-  long len;
-};
-
 void llist_free_arg(void *node);
 void llist_free_double(void *node);
 void llist_traverse(void *list, void (*using)(void *node));
@@ -193,6 +198,23 @@ int xpoll(struct pollfd *fds, int nfds, int timeout);
 #define HR_1000  4 // Use decimal instead of binary units
 int human_readable(char *buf, unsigned long long num, int style);
 
+// linestack.c
+
+struct linestack {
+  long len, max;
+  struct ptr_len idx[];
+};
+
+void linestack_addstack(struct linestack **lls, struct linestack *throw,
+  long pos);
+void linestack_insert(struct linestack **lls, long pos, char *line, long len);
+void linestack_append(struct linestack **lls, char *line);
+struct linestack *linestack_load(char *name);
+int crunch_str(char **str, int width, FILE *out,
+  int (*escout)(FILE *out, wchar_t wc));
+int draw_str(char *start, int width, int (*escout)(FILE *out, wchar_t wc));
+int draw_rstr(char *start, int width, int (*escout)(FILE *out, wchar_t wc));
+
 // interestingtimes.c
 int xgettty(void);
 int terminal_size(unsigned *xx, unsigned *yy);
@@ -234,6 +256,8 @@ struct mtab_list {
   char type[0];
 };
 
+void comma_args(struct arg_list *al, void *data, char *err,
+  char *(*callback)(void *data, char *str, int len));
 void comma_collate(char **old, char *new);
 char *comma_iterate(char **list, int *len);
 int comma_scan(char *optlist, char *opt, int clean);
@@ -256,6 +280,8 @@ void names_to_pid(char **names, int (*callback)(pid_t pid, char *name));
 pid_t xvforkwrap(pid_t pid);
 #define XVFORK() xvforkwrap(vfork())
 
+// Wrapper to make xfuncs() return (via longjmp) instead of exiting.
+// Assigns true/false "did it exit" value to first argument.
 #define WOULD_EXIT(y, x) do { jmp_buf _noexit; \
   int _noexit_res; \
   toys.rebound = &_noexit; \
@@ -265,6 +291,7 @@ pid_t xvforkwrap(pid_t pid);
   y = _noexit_res; \
 } while(0);
 
+// Wrapper that discards true/false "did it exit" value.
 #define NOEXIT(x) WOULD_EXIT(_noexit_res, x)
 
 // Functions in need of further review/cleanup
diff --git a/lib/linestack.c b/lib/linestack.c
new file mode 100644
index 00000000..b06c97e7
--- /dev/null
+++ b/lib/linestack.c
@@ -0,0 +1,118 @@
+#include "toys.h"
+
+// Insert one stack into another before position in old stack.
+// (Does not copy contents of strings, just shuffles index array contents.)
+void linestack_addstack(struct linestack **lls, struct linestack *throw,
+  long pos)
+{
+  struct linestack *catch = *lls;
+
+  if (CFG_TOYBOX_DEBUG)
+    if (pos > catch->len) error_exit("linestack_addstack past end.");
+
+  // Make a hole, allocating more space if necessary.
+  if (catch->len+throw->len >= catch->max) {
+    // New size rounded up to next multiple of 64, allocate and copy start.
+    catch->max = ((catch->len+throw->len)|63)+1;
+    *lls = xmalloc(sizeof(struct linestack)+catch->max*sizeof(struct ptr_len));
+    memcpy(*lls, catch, sizeof(struct linestack)+pos*sizeof(struct ptr_len));
+  }
+
+  // Copy end (into new allocation if necessary)
+  if (pos != catch->len)
+    memmove((*lls)->idx+pos+throw->len, catch->idx+pos,
+      (catch->len-pos)*sizeof(struct ptr_len));
+
+  // Cleanup if we had to realloc.
+  if (catch != *lls) {
+    free(catch);
+    catch = *lls;
+  }
+
+  memcpy(catch->idx+pos, throw->idx, throw->len*sizeof(struct ptr_len));
+  catch->len += throw->len;
+}
+
+void linestack_insert(struct linestack **lls, long pos, char *line, long len)
+{
+  // alloca() was in 32V and Turbo C for DOS, but isn't in posix or c99.
+  // I'm not thrashing the heap for this, but this should work even if
+  // a broken compiler adds gratuitous padding.
+  struct {
+    struct linestack ls;
+    struct ptr_len pl;
+  } ls;
+
+  ls.ls.len = ls.ls.max = 1;
+  ls.ls.idx[0].ptr = line;
+  ls.ls.idx[0].len = len;
+  linestack_addstack(lls, &ls.ls, pos);
+}
+
+void linestack_append(struct linestack **lls, char *line)
+{
+  linestack_insert(lls, (*lls)->len, line, strlen(line));
+}
+
+struct linestack *linestack_load(char *name)
+{
+  FILE *fp = fopen(name, "r");
+  struct linestack *ls;
+
+  if (!fp) return 0;
+
+  ls = xzalloc(sizeof(struct linestack));
+
+  for (;;) {
+    char *line = 0;
+    ssize_t len;
+
+    if ((len = getline(&line, (void *)&len, fp))<1) break;
+    if (line[len-1]=='\n') len--;
+    linestack_insert(&ls, ls->len, line, len);
+  }
+  fclose(fp);
+
+  return ls;
+}
+
+// Show width many columns, negative means from right edge. Write unprintable
+// chars through escout() instead of write(). If out=0 just measure.
+// Returns width in columns.
+int crunch_str(char **str, int width, FILE *out,
+  int (*escout)(FILE *out, wchar_t wc))
+{
+  int columns = 0, col, bytes, lowlen = escout(0, 0);
+  char *start, *end;
+
+  for (end = start = *str; *end;) {
+    wchar_t wc;
+
+    if (width>=0 && columns+lowlen>width) break;
+
+    bytes = mbrtowc(&wc, end, 99, 0);
+    if (bytes<0 || wc<32 || (col = wcwidth(wc))<0) {
+      bytes = 1;
+      col = escout(out, *end);
+    } else if (out) fwrite(end, bytes, 1, out);
+    end += bytes;
+  }
+  *str = end;
+
+  return columns;
+}
+
+int draw_str(char *start, int width, int (*escout)(FILE *out, wchar_t wc))
+{
+  return crunch_str(&start, width, stdout, escout);
+}
+
+int draw_rstr(char *start, int width, int (*escout)(FILE *out, wchar_t wc))
+{
+  char *s = start;
+  int len = crunch_str(&s, -1, 0, escout);
+
+  s = start;
+  if (len > width) crunch_str(&s, len-width, 0, escout);
+  return crunch_str(&s, width, stdout, escout);
+}