I just started shell scripting, and I need to check if a file exists so I used command :
if [[-e "./doc/issues/$1.md" ]];
But the command seems to be invalid.
Does anybody knows why ?
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1 Answer
You forgot to put a whitespace before -e, try :
if [[ -e "./doc/issues/$1.md" ]];
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2The reason the space is required is that
[[is not mere syntax: it is (essentially) a command, and like every command, it needs a space to separate it from its arguments. Commented May 3, 2019 at 14:23 -
Spaces are critical parts of shell syntax; there are places where they're required (like between
[[and-e-- and also-eand the filename, and the filename and]]), and places where they're not allowed (like around the=in an assignment), but very few places where they're optional. When copying an example, be sure to copy the spacing along with everything else. Commented May 3, 2019 at 15:00 -
Or in other words: shell scripts work with words. 2 words are usually separated by any number of space, tabs or linefeeds. quotes are used to create words with included spaces/tabs. So
[[-eis one word without special meaning. I contrast,[[ -eare 2 words.[[opens a condition test mode and-eis a condition that accepts the next word as param.– WiimmCommented May 4, 2019 at 20:38