Why testing for first character skips empty lines?












0














Why does the following file reader and commented line check skip the empty lines?



while read line; do

    if [ ! ${line:0:1} == "#" ]; then # leave out comments

            function_call $line

    fi

done < list_items.txt





bash







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  • 2




    Quotes What's more interesting, is why [ ! == '#' ] returns false.
    – Kamil Cuk
    2 days ago


















0














Why does the following file reader and commented line check skip the empty lines?



while read line; do

    if [ ! ${line:0:1} == "#" ]; then # leave out comments

            function_call $line

    fi

done < list_items.txt





bash







share|improve this question







New contributor




Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
















  • 2




    Quotes What's more interesting, is why [ ! == '#' ] returns false.
    – Kamil Cuk
    2 days ago
















0












0








0







Why does the following file reader and commented line check skip the empty lines?



while read line; do

    if [ ! ${line:0:1} == "#" ]; then # leave out comments

            function_call $line

    fi

done < list_items.txt





bash







share|improve this question







New contributor




Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











Why does the following file reader and commented line check skip the empty lines?



while read line; do

    if [ ! ${line:0:1} == "#" ]; then # leave out comments

            function_call $line

    fi

done < list_items.txt





bash




bash






share|improve this question







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Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question







New contributor




Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question






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Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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asked 2 days ago









Johannes Almiala

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Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor





Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Johannes Almiala is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








  • 2




    Quotes What's more interesting, is why [ ! == '#' ] returns false.
    – Kamil Cuk
    2 days ago
















  • 2




    Quotes What's more interesting, is why [ ! == '#' ] returns false.
    – Kamil Cuk
    2 days ago










2




2




Quotes What's more interesting, is why [ ! == '#' ] returns false.
– Kamil Cuk
2 days ago






Quotes What's more interesting, is why [ ! == '#' ] returns false.
– Kamil Cuk
2 days ago














1 Answer
1






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oldest

votes


















1














Behavior of skipping empty lines is caused by non-quoting bash variable, always quote when comparing strings:



while read line; do

    if [ ! "${line:0:1}" == "#" ]; then # leave out comments

            function_call "${line}"

    fi

done < list_items.txt


Above will handle empty lines.






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    Behavior of skipping empty lines is caused by non-quoting bash variable, always quote when comparing strings:



    while read line; do
    
    if [ ! "${line:0:1}" == "#" ]; then # leave out comments
    
            function_call "${line}"
    
    fi
    
done < list_items.txt


    Above will handle empty lines.






    share|improve this answer




























      1














      Behavior of skipping empty lines is caused by non-quoting bash variable, always quote when comparing strings:



      while read line; do
      
    if [ ! "${line:0:1}" == "#" ]; then # leave out comments
      
            function_call "${line}"
      
    fi
      
done < list_items.txt


      Above will handle empty lines.






      share|improve this answer


























        1












        1








        1






        Behavior of skipping empty lines is caused by non-quoting bash variable, always quote when comparing strings:



        while read line; do
        
    if [ ! "${line:0:1}" == "#" ]; then # leave out comments
        
            function_call "${line}"
        
    fi
        
done < list_items.txt


        Above will handle empty lines.






        share|improve this answer














        Behavior of skipping empty lines is caused by non-quoting bash variable, always quote when comparing strings:



        while read line; do
        
    if [ ! "${line:0:1}" == "#" ]; then # leave out comments
        
            function_call "${line}"
        
    fi
        
done < list_items.txt


        Above will handle empty lines.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 2 days ago

























        answered 2 days ago









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