is there an 'upwards' find?

Question

I found I asked this question on the wrong stackexchange site.

To find files starting from a certain path, I can use find <path> .... If I want to find 'upwards', i.e. in the parent directory, and it's parent, and..., is there an equivalent tool?

The use case is knowing the right number of dots (../../x.txt or ../../../x.txt?) to use in e.g. a makefile including some common makefile functions somewhere upstream.

Intended usage for a folder structure like this:

/
/abc
/abc/dce/efg/ghi
/abc/dce/efg2


$ cd /abc/dce/efg/ghi
$ touch ../../x.txt
$ upfind . -name X*
../../x.txt
$ upfind . -name Y* || echo "not found"
not found
$ touch /abc/dce/efg2/x.txt
$ upfind . -name Y* || echo "not found"
not found
$ 

So in short:

• it should search on this folder, it's parent, it's parent's parent...
• but not in any of their siblings (like 'find' would)
• it should report the found file(s) relative to the current path

Answer 1

Existing answers unsufficient (details below).

#!/usr/bin/env bash

DIR=$(readlink -f "$1")
# Alternative: use current working dir; but then also replace ${@:2} with $@ on line 8
# and $1 with $PWD when calling realpath
# DIR=$PWD

while
  RESULT=$(find "$DIR"/ -maxdepth 1 "${@:2}")
  # echo "Debugging upfind - search in $DIR gives: $RESULT"
  [[ -z $RESULT ]] && [[ "$DIR" != "/" ]]
do DIR=$(dirname "$DIR"); done

realpath --relative-to="$1" "$RESULT"
# Alternative: output absolute path
# echo "$RESULT"

The two alternatives you might consider can be toggled in the script; using $PWD instead of the first parameter means we need to pass $@ (all parameters) to find, and outputting the full path instead of a relative path by commenting the realpath line and just echoing $RESULT.

Note use of a do-while loop is from this SO answer.

Choroba and Matthew Wolff got the end condition wrong; so they would fail to find a file that is actually in the root of the filesystem. They also both do cd's, which is not something I want bash scripts to do. Peter O's solution looks better, but simply outputs nothing for my constructed testcase, and it's easier to write a new bash script than to debug an existing one.

Answer 2

You can use this simple script. It walks the directory tree upwards and searches for the specified files.

#! /bin/bash
prev=.
while [[ $PWD != "$prev" ]] ; do
    find "$PWD" -maxdepth 1 "$@"
    prev=$PWD
    cd ..
done

Usage:

upfind -name 'x*'

Answer 3

You can just split the path into its constituent directory nodes and search each one discreetly. It is a bash script.

IFS=/; dn=($1); ct=${#dn[@]}
for((i=0; i<ct; i++)); do
  subd+=/"${dn[i]}"
  dots=$(for((j=ct-i; j>1; j--)); do printf "../"; done)
  find "$subd" -maxdepth 1 -type f -name "$2" -printf "$dots%f\n"
done

run upfind $HOME/zt" "Y*" ... which produces the following output
when YABBA exists in /, /home/user, /home/user/zt

../../../YABBA
../YABBA
YABBA

Answer 4

Expanding on @choroba's answer with my own solution for finding the upward location of a file (by name):

upfind() {
  ORIG_DIR="$PWD"
  while [[ "$PWD" != / ]] ; do
    if find "$PWD"/ -maxdepth 1 -type f -name "$@" | grep -q "$@"; then
      echo "$PWD" && builtin cd "$ORIG_DIR"
      return 0
    else
      builtin cd ..
    fi
  done
  builtin cd "$ORIG_DIR"
  return 1
}

Example:

> upfind packageInfo
/home/matthew/development/packageRoot

It will return with an error code, which is useful if you're using it in a conditional. However, this solution is less of an upward version of find (I assume it won't play nice when you pass in additional parameters) as it is a specific solution to finding a file by name.

Answer 5

In case someone is looking for something similar but more concise for interactive shell

Bash

You can define a short recursive function:

upfind () {
  ls -d $1 || upfind ../$1
}

Zsh

A one-liner is possible. Unfortunately, you'll need to manually press Enter a few times.

ls -d ./.git || pushln '^./^./../^'

pushln makes ^./^./../^ be waiting for you in your next prompt which in turn expands into the same command but with added ../