I would try:

sudo find / -type d -name "postgis-2.0.0"

The . means search only in the current directory, it is best to search everything from root if you really don't know. Also, type -f means search for files, not folders. Adding sudo allows it to search in all folders/subfolders.

Your syntax for locate is correct, but you may have to run

sudo updatedb

first. For whatever reason, I never have good luck with locate though.

locate uses database of files and directories made by updatedb. So if you have downloaded a new file there is more chance that your updatedb has not updated the database of files and directories. You can use sudo updatedb before using locate utility program. updatedb generally runs once a day by itself on linux systems.

find is one of the most useful Linux/Unix tools.

Try find . -type d | grep DIRNAME

The other answers are good, but I find omitting Permission denied statements gives me clearer answers (omits stderrs due to not running sudo):

find / -type f -iname "*postgis-2.0.0*" 2>/dev/null

where:

• / can be replaced with the directory you want to start your search from
• f can be replaced with d if you're searching for a directory instead of a file
• -iname can be replaced with -name if you want the search to be case sensitive
• the *s in the search term can be omitted if you don't want the wildcards in the search

An alternative is:

find / -type f 2>/dev/null | grep "postgis-2.0.0"

This way returns results if the search-term matches anywhere in the complete file path, e.g. /home/postgis-2.0.0/docs/Readme.txt

Try find . -name "*file_name*"

• where you can change '.'(look into the Current Directory) to '/'(look into the entire system) or '~/'(look into the Home Directory).

• where you can change "-name" to "-iname" if you want no case sensitive.

• where you can change "file_name"(a file that can start and end with whatever it is) to the exactly name of the file.

This should simplify the locating of file:

This would give you the full path to the file

tree -f  / | grep postgis-2.0.0

Tree lists the contents of directories in a tree-like format. the -f tells tree to give the full path to the file. since we have no idea of its location or parent location, good to search from the filesystem root / recursively downwards. We then send the output to grep to highlight our word, postgis-2.0.0

While find command is simplest way to recursively traverse the directory tree, there are other ways and in particular the two scripting languages that come with Ubuntu by default already have the ability to do so.

bash

bash has a very nice globstar shell option, which allows for recursive traversal of the directory tree. All we need to do is test for whether item in the ./**/* expansion is a file and whether it contains the desired text:

bash-4.3$ for f in ./**/* ;do [ -f "$f" ] && [[ "$f" =~ "postgis-2.0.0" ]] && echo "$f"; done 
./testdir/texts/postgis-2.0.0

Perl

Perl has Find module, which allows to perform recursive traversal of directory tree, and via subroutine perform specific action on them. With a small script, you can traverse directory tree, push files that contain the desired string into array, and then print it like so:

#!/usr/bin/env perl
use strict;
use warnings;
use File::Find;

my @wanted_files;
find(
     sub{ 
         -f $_ && $_ =~ $ARGV[0]  
               && push @wanted_files,$File::Find::name
     }, "."
);

foreach(@wanted_files){
    print "$_\n"
}

And how it works:

$ ./find_file.pl  "postgis-2.0.0"                                                       
./testdir/texts/postgis-2.0.0

Python

Python is another scripting language that is used very widely in Ubuntu world. In particular, it has os.walk() module which allows us to perform the same action as above - traverse directory tree and obtain list of files that contain desired string.

As one-liner this can be done as so:

$ python -c 'import os;print([os.path.join(r,i) for r,s,f in os.walk(".") for i in f if "postgis-2.0.0" in i])'                                                                         
['./testdir/texts/postgis-2.0.0']

Full script would look like so:

#!/usr/bin/env python
import os;

for r,s,f in os.walk("."):
    for i in f:
        if "postgis-2.0.0" in i:
            print(os.path.join(r,i))

$ find . -type f | grep IMG_20171225_*
Gives
./03-05--2018/IMG_20171225_200513.jpg
The DOT after the command find is to state a starting point,
Hence - the current folder,
"piped" (=filtered) through the name filter IMG_20171225_*