Find Command – Avoid Multiple Levels of Symlinks

findsymlink

I know the thread and try to fix my find with -mindepth 15 unsuccessfully

find -L $HOME -type f -name "*.tex" \
   -exec fgrep -l "janne" /dev/null {} + | vim -R -

Unsuccessful attempt

find -L $HOME -type f -mindepth 15 -name "*.tex" \
   -exec fgrep -l "janne" /dev/null {} + | vim -R -

find -L about it here

Its STOUT

Vim: Reading from stdin...
find: ‘/home/masi/LOREM’: Too many levels of symbolic links

Visualization of symlinks unsuccessful which gives all files while I would like to see only symlinked directories and files in the system

tree -l

Law29's proposal

# include symlinks
find "$1" -type l -name "$2*" -print0 \
    | xargs -0 grep -Hr --include "*.tex" "$2" /dev/null {} + | vim -R -

Output unsuccessful but it should not be empty

Vim: Reading from stdin...
grep: {}: No such file or directory
grep: +: No such file or directory

Characteristics of the system

masi@masi:~$ ls -ld -- "$HOME" /home/masi/LOREM 
drwxr-xr-x 52 masi masi 4096 Aug 16 16:09 /home/masi
lrwxrwxrwx  1 masi masi   17 Jun 20 00:27 /home/masi/LOREM -> /home/masi/LOREM/

masi@masi:~$ type find
find is /usr/bin/find

masi@masi:~$ find --version
find (GNU findutils) 4.7.0-git
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Eric B. Decker, James Youngman, and Kevin Dalley.
Features enabled: D_TYPE O_NOFOLLOW(enabled) LEAF_OPTIMISATION FTS(FTS_CWDFD) CBO(level=2)

System: Linux Ubuntu 16.04 64 bit
For for Script at the thread: here
Find: 4.7.0
Grep: 2.25
Application of find: haetex here

Best Answer

If you want to display all files under $HOME, including those referenced via symbolic links, that end with .tex and contain the string janne:

find -L "$HOME" -type f -name '*.tex' -exec grep -l 'janne' {} + 2>/dev/null | vim -R -

If you want to display only symbolic links found under $HOME named *.tex corresponding to files that contain the string janne:

find -L "$HOME" -xtype l -name '*.tex' -exec grep -l 'janne' {} + 2>/dev/null | vim -R -

The only way to avoid the error message "Too many levels of symbolic links" is to discard all errors, which I've done with the 2>/dev/null construct.

In both cases the find verb will not traverse across files and directories that it has already traversed - it remembers where it's already visited and prunes those parts of the filesystem tree automatically. For example,

mkdir a a/b a/b/c
cd a/b/c
ln -s ../../../a

# Here you can ls a/b/c/a/b/c/a/b/...

# But find will not continue for very long
find -L a
a
a/b
a/b/c
find: File system loop detected; ‘a/b/c/a’ is part of the same file system loop as ‘a’.

Related Solutions

shell – How to Find Broken Symlinks

I'd strongly suggest not to use find -L for the task (see below for explanation). Here are some other ways to do this:

If you want to use a "pure find" method, it should rather look like this:
```
find . -xtype l
```
(xtype is a test performed on a dereferenced link) This may not be available in all versions of find, though. But there are other options as well:
You can also exec test -e from within the find command:
```
find . -type l ! -exec test -e {} \; -print
```
Even some grep trick could be better (i.e., safer) than find -L, but not exactly such as presented in the question (which greps in entire output lines, including filenames):
```
 find . -type l -exec sh -c 'file -b "$1" | grep -q ^broken' sh {} \; -print
```

The find -L trick quoted by solo from commandlinefu looks nice and hacky, but it has one very dangerous pitfall: All the symlinks are followed. Consider directory with the contents presented below:

$ ls -l
total 0
lrwxrwxrwx 1 michal users  6 May 15 08:12 link_1 -> nonexistent1
lrwxrwxrwx 1 michal users  6 May 15 08:13 link_2 -> nonexistent2
lrwxrwxrwx 1 michal users  6 May 15 08:13 link_3 -> nonexistent3
lrwxrwxrwx 1 michal users  6 May 15 08:13 link_4 -> nonexistent4
lrwxrwxrwx 1 michal users 11 May 15 08:20 link_out -> /usr/share/

If you run find -L . -type l in that directory, all /usr/share/ would be searched as well (and that can take really long)¹. For a find command that is "immune to outgoing links", don't use -L.

¹ This may look like a minor inconvenience (the command will "just" take long to traverse all /usr/share) – but can have more severe consequences. For instance, consider chroot environments: They can exist in some subdirectory of the main filesystem and contain symlinks to absolute locations. Those links could seem to be broken for the "outside" system, because they only point to proper places once you've entered the chroot. I also recall that some bootloader used symlinks under /boot that only made sense in an initial boot phase, when the boot partition was mounted as /.

So if you use a find -L command to find and then delete broken symlinks from some harmless-looking directory, you might even break your system...

How to remove a directory with “Too many levels of symlinks”

Try find.

find -L /gluster_broken -mindepth 10

to find the link loops

then a non recursive rm on the erroneous file(s)

find will follow links and find the same "too many levels" error. I use -mindepth to filter out anything less than 10 deep to avoid the ok files/directories. Yes, this does assume that you don't have more that 10 deep in your normal tree. All this command is trying to do is find the file in error.

-- edit

I think following command is better,

find -L /gluster_broken >/dev/null

Here's my test

$ find .
.
./dira
./dira/a
./dira/dirb
./dira/dirb/dirc
./dira/error
./dira/b
./dira/test
./dira/test/ab&<cd.file
./dira/test/magic?newlines
./dira/test/cleanup
$ find -L . >/dev/null
find: ‘./dira/a’: Too many levels of symbolic links
find: ‘./dira/error’: Too many levels of symbolic links
find: ‘./dira/b’: Too many levels of symbolic links
$

--- edit 2

I think my suggestion (comment) to check file-system might be best, I have just seen this answer and wonder if you have a similar issue.

Law29's proposal

Best Answer

Related Solutions

shell – How to Find Broken Symlinks

How to remove a directory with “Too many levels of symlinks”

Related Question