echo to file - error: cannot create - unix

Question

In Unix ksh. I am trying to create a text file with few lines of text in it using below echo statement
echo $multilinetext > ../in/log_file
The error i am getting is "Cannot Create". Also this code worked fine before some time.
Through filezilla i am able to create the file. The "in" directory has all permissions(777).
the Dir hierarchy is as below
ParentDir
in
Bin
test.ksh
test.ksh is executing the echo command
What else should be causing the error
Update:
The problem was that i executed the script from parentDir. So instead of saying the file does not exist, it found the test.ksh file in Bin and executed it without any errors. which caused it to look for "in" directory in wrong location
Is it possible to check if the script is executed from its own directory?

Answer 1

Per your request, here's a small script based on what you've posted about your hierarchy:
#!/bin/sh -
# adjust this to suit
bin_dir="/tmp/top/bin"
multi=`cat /etc/passwd`
# get current directory
pwd="`pwd`"
# check to ensure we're in the correct directory
if [ "$pwd" != "$bin_dir" ]; then
echo "not executing from correct bin directory"
exit
fi
target_dir="../in"
# ensure the target directory for writing exists
if [ -d "$target_dir" ]; then
echo $multi > $target_dir/log_file
else
echo "unable to locate directory '$target_dir' -- does not exist"
fi