Bug#821750: option to follow symlinks

[Antoine Beaupré]

Package: ncdu
Version: 1.10-1
Severity: wishlist

I understand why ncdu doesn't count symlinks by default, but in some
cases, it would be very useful to do so. My use case is specifically
about git-annex repositories, which make heavy use of symlinks.

There is a patch in the upstream bugtracker, but the thread has been
inactive for a few years now:

https://dev.yorhel.nl/ncdu/bug/16
https://p.blicky.net/j3py5

A copy of the patch is attached.

-- System Information:
Debian Release: 8.4
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'proposed-updates'), (500, 
'stable'), (1, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.2.0-0.bpo.1-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_CA.UTF-8, LC_CTYPE=fr_CA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages ncdu depends on:
ii  libc6         2.19-18+deb8u4
ii  libncursesw5  5.9+20140913-1+b1
ii  libtinfo5     5.9+20140913-1+b1

ncdu recommends no packages.

ncdu suggests no packages.

-- no debconf information

diff --git a/src/dir_scan.c b/src/dir_scan.c
index 6c38eeb..0b9d679 100644
--- a/src/dir_scan.c
+++ b/src/dir_scan.c
@@ -188,7 +188,7 @@ static int dir_scan_item(struct dir *d) {
   if(exclude_match(dir_curpath))
     d->flags |= FF_EXL;
 
-  if(!(d->flags & (FF_ERR|FF_EXL)) && lstat(d->name, &st)) {
+  if(!(d->flags & (FF_ERR|FF_EXL)) && (follow_symlinks ? stat : lstat)(d->name, &st)) {
     d->flags |= FF_ERR;
     dir_setlasterr(dir_curpath);
   }
diff --git a/src/global.h b/src/global.h
index e298f1e..4ef8bc6 100644
--- a/src/global.h
+++ b/src/global.h
@@ -84,6 +84,8 @@ struct dir {
 extern int pstate;
 /* read-only flag */
 extern int read_only;
+/* Whether to follow symlinks */
+extern int follow_symlinks;
 /* minimum screen update interval when calculating, in ms */
 extern long update_delay;
 /* filter directories with CACHEDIR.TAG */
diff --git a/src/main.c b/src/main.c
index 2e30d25..5b5e5f1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -39,6 +39,7 @@
 
 int pstate;
 int read_only = 0;
+int follow_symlinks = 0;
 long update_delay = 100;
 int cachedir_tags = 0;
 
@@ -119,6 +120,7 @@ static void argv_parse(int argc, char **argv) {
     { 'v', 0, "-v" },
     { 'x', 0, "-x" },
     { 'r', 0, "-r" },
+    { 'L', 0, "-L" },
     { 'o', 1, "-o" },
     { 'f', 1, "-f" },
     { '0', 0, "-0" },
@@ -159,6 +161,7 @@ static void argv_parse(int argc, char **argv) {
       exit(0);
     case 'x': dir_scan_smfs = 1; break;
     case 'r': read_only = 1; break;
+    case 'L': follow_symlinks = 1; break;
     case 's': si = 1; break;
     case 'o': export = val; break;
     case 'f': import = val; break;