bash - storing absolute path to a file inside a variable

Question

I'm trying to figure out why

[ -d ~/dir ] ; echo $?

indeed returns 0, if dir exists and is a directory, but

DIR="~/dir" ; [ -d "${DIR}" ] ; echo $?

always returns 1.

echo "${DIR}"

prints ~/dir, as expected. I am given a text file containing path to another file, and thought I'd use cat to store the content inside a variable. What is the proper way to do this?

http://stackoverflow.com/questions/3963716/how-to-manually-expand-a-special-variable-ex-tilde-in-bash/27485157#27485157 — ewcz, Mar 08 '17 at 10:40

score 0 · Accepted Answer · answered Mar 08 '17 at 10:39

0

The tilde expansion happens before the variable expansion, see EXPANSION in man bash. ~ is not a real path, it's expanded by the shell to the real path, but it doesn't happen for paths stored in a variable. Store the real full path in the variable instead.

answered Mar 08 '17 at 10:39

choroba

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Now it makes sense. Thank you so much! – confused_but_determinated Mar 08 '17 at 10:42
"Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score." Also, I was not able to accept an answer that soon. You'll get your credit, don't worry. – confused_but_determinated Mar 08 '17 at 10:48

score 0 · Answer 2 · answered Mar 08 '17 at 10:45

0

not really a bash solution but you could do:

DIR="~/dir" ;

#expand the tilde
DIR=$(python -c "import os;print(os.path.expanduser('${DIR}'));");

[ -d "${DIR}" ] ; echo $?

answered Mar 08 '17 at 10:45

ewcz

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score 0 · Answer 3 · answered Dec 21 '18 at 10:32

0

DIR = "$HOME/dir" would work fine.

answered Dec 21 '18 at 10:32

Areeb

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bash - storing absolute path to a file inside a variable

3 Answers3