Bash script to test file existence

Question

I'm trying to check if the filespaths written in a txt file (of user jane) are present in the system. This is the file list.txt:

001 jane /data/jane_profile_07272018.doc
002 kwood /data/kwood_profile_04022017.doc
003 pchow /data/pchow_profile_05152019.doc
004 janez /data/janez_profile_11042019.doc
005 jane /data/jane_pic_07282018.jpg
006 kwood /data/kwood_pic_04032017.jpg
007 pchow /data/pchow_pic_05162019.jpg
008 jane /data/jane_contact_07292018.csv
009 kwood /data/kwood_contact_04042017.csv
010 pchow /data/pchow_contact_05172019.csv

This is the script I wrote:

#!/bin/bash
file=$(grep ' jane ' ../data/list.txt | cut -d ' ' -f 3)
for i in $file
do
  i="~${i}"
  if (test -e $i); then echo "File exists"; else echo "File doesn't exist"; fi
done

I don't understand why the command

test -e ~/data/jane_profile_07272018.doc

is true, but when I write it like in the script above it returns false. Is it related to the way i'm adding the ~? Without it the command by itself returns false.

I think ~ only works from the bash command-line. Try $HOME instead? — Gem Taylor
– Gem Taylor, Commented Mar 23, 2020 at 12:04
~ will work in scripts, but not if it's in quotes (as it is here). So try i="${HOME}${i}" instead. — Gordon Davisson
– Gordon Davisson, Commented Mar 23, 2020 at 16:04
awk '$2 == "jane" {cmd = "if test -e $HOME" $NF "; then echo file $HOME" $NF " exists; else echo file $HOME" $NF " does not exists; fi"; system(cmd)}' file.txt — Jetchisel
– Jetchisel, Commented Apr 19 at 9:19

Matt Shin · Accepted Answer · 2020-03-23 12:09:07Z

1

The ~ in front of ~/data/jane_profile_07272018.doc is roughly equivalent to $HOME/data/jane_profile_07272018.doc. So instead of looking for the file under root /, it is looking for the file under your HOME directory.

You should do:

if [[ -e "$file" ]]; then
    echo "$file: exists"
else
    echo "file: does not exist"
fi

answered Mar 23, 2020 at 12:09

Matt Shin

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1 Comment

Léa Gris Over a year ago

while IFS= read -r f; do p="$HOME/$f"; if [ -e "$p" ]; then printf '%s exists\n' "$p"; fi; done < <(sed -n 's/^[[:digit:]]\+ jane //p' list.txt)

massisenergy · Accepted Answer · 2025-04-25 05:16:29Z

0

~ doesn't expand inside double quotes " " or when assigned to a variable as a string, so it remains a literal ~.

Using $HOME will ensure correct expansion to the home directory regardless of quotes.

CORRECT SCRIPT:

#!/bin/bash

file=$(grep ' jane ' ../data/list.txt | cut -d ' ' -f 3)

for i in $file; do
  i="$HOME$i"
  if [ -e "$i" ]; then
    echo "File exists"
  else
    echo "File doesn't exist"
  fi
done

edited Apr 25 at 5:16

massisenergy

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answered Apr 19 at 8:21

PK443

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