Hüseyin Orkun Elmas Hüseyin Orkun Elmas - 2 months ago 8
JSON Question

I am trying to write a bash script that uses aspell to check spell check files

I have the following script at hand, i think there are errors but i don't have the knowledge to fix them. The problem is that the script returns nothing but it is supposed to return misspelled words. I run this script with this command

$ sh ./action.sh "{\"b64\":\"`base64 input.txt`\" }"


input.txt has 6 words:
Cat dog
elephent lion
mooose bug

and it returns

{ "result": "" }


but i want it to return

{ "result": "elephent mooose " }

#!/bin/bash
#
# This script expects one argument, a String representation of a JSON
# object with a single attribute called b64. The script decodes
# the b64 value to a file, and then pipes it to aspell to check spelling.
# Finally it returns the result in a JSON object with an attribute called
# result
#
FILE=/home/user/output.txt

# Parse the JSON input ($1) to extract the value of the 'b64' attribute,
# then decode it from base64 format, and dump the result to a file.
echo $1 | sed -e 's/b64.://g' \
| tr -d '"' | tr -d ' ' | tr -d '}' | tr -d '{' \
| base64 --decode >&2 $FILE

# Pipe the input file to aspell, and then format the result on one line with
# spaces as delimiters
RESULT=`cat $FILE | aspell list | tr '\n' ' ' `

# Return a JSON object with a single attribute 'result'
echo "{ \"result\": \"$RESULT\" }"

Answer Source

I think, the problem is about redirecting. I changed >&2 $FILE to > $FILE 2>&1 then it works. (I don't know why first one is not ok)

Here is the output:

yavuz@ubuntu:/tmp$ sh ./action.sh "{\"b64\":\"`base64 input.txt`\" }"
{ "result": "elephent mooose " }

Code:

#!/bin/bash
#
# This script expects one argument, a String representation of a JSON
# object with a single attribute called b64.   The script decodes
# the b64 value to a file, and then pipes it to aspell to check spelling.
# Finally it returns the result in a JSON object with an attribute called
# result
#
FILE=/tmp/output.txt

# Parse the JSON input ($1) to extract the value of the 'b64' attribute,
# then decode it from base64 format, and dump the result to a file.
echo $1 | sed -e 's/b64.://g' \
        | tr -d '"' | tr -d ' ' | tr -d '}' | tr -d '{' \
        | base64 --decode > $FILE 2>&1

# Pipe the input file to aspell, and then format the result on one line with
# spaces as delimiters
RESULT=`cat $FILE | aspell list | tr '\n' ' ' `

# Return a JSON object with a single attribute 'result'
echo "{ \"result\": \"$RESULT\" }"