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Mkdir fails when defined and called with functions.

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# 1  
Old 12-14-2016
Hammer & Screwdriver Mkdir fails when defined and called with functions.
In the below script i found that the alias mkdir_s is getting invoked from function configure() i.e the alias is kicking in.

Code:
#!/bin/bash -e
shopt -s expand_aliases

alias mkdir=mkdir_s
mkdir_s(){
if [[ -d $1 ]]; then
return
else
/usr/bin/mkdir "$1"
return
fi
}

configure()
{
mkdir -p /tmp/logs
}

configure

Inside the mkdir_s function it is also able to check the condition if the directory does not exist and executes the mkdir command. but then, I get the following error as the output.

Quote:
mkdir: usage: mkdir [-m mode] [-p] dirname ...

Can you please explain why and what is the fix ?
# 2  
Old 12-14-2016
This is because in this case $1 equals -p (and $2 equals /tmp/logs, but that is not being used inside the function)
# 3  
Old 12-14-2016
Quote:
Originally Posted by Scrutinizer
This is because in this case $1 equals -p (and $2 equals /tmp/logs, but that is not being used inside the function)
So, how can we optimize the function mkdir_s so as to understand the difference between mkdir dir and mkdir -p dir and act accordingly.

This is what i think will take care of the problem.

Code:
mkdir_s(){
var1=$1
if [[ $var1 == -* ]]; then var2=$2; else var2=var1; fi
if [[ -d $var2 ]]; then
#echo " directory EXISTS "
return
else
#echo " Creating DIRECTORY"
/usr/bin/mkdir "$var2"
return
fi
}

Let me know if you have other suggestions.
Last edited by mohtashims; 12-14-2016 at 03:32 PM..
# 4  
Old 12-14-2016
Quote:
Originally Posted by mohtashims
So, how can we optimize the function mkdir_s so as to understand the difference between mkdir dir and mkdir -p dir and act accordingly.
What are you going to do about mkdir's other options? Pehaps someone wants a dir created with a specific mode via -m, or has to use your script under SElinux and needs -Z.

Are you going to completely re-implement mkdir feature-by-feature?

What exactly is your goal here in intercepting mkdir?
# 5  
Old 12-14-2016
Tools
Quote:
Originally Posted by Corona688
What are you going to do about mkdir's other options? Pehaps someone wants a dir created with a specific mode via -m, or has to use your script under SElinux and needs -Z.

Are you going to completely re-implement mkdir feature-by-feature?

What exactly is your goal here in intercepting mkdir?
Good Question.

The only reason i m doing this is To avoid mkdir to error out [avoid exit 1 code i.e handle it] incase the directory already exists. Thats the only purpose of my efforts.
# 6  
Old 12-14-2016
Quote:
Originally Posted by mohtashims
Good Question.

The only reason i m doing this is To avoid mkdir to error out [avoid exit 1 code i.e handle it] incase the directory already exists. Thats the only purpose of my efforts.
Then just use mkdir -p, which will not fail when directory already exists:

Code:
$ mkdir -p /tmp && echo "I did not fail"
I did not fail

$

# 7  
Old 12-14-2016
mkdir -p won't error out if a directory branch exists.
You can
- simply ignore an error exit code of mkdir.
- use getopts in your function.
- use a compiler to rewrite the mkdir command.
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