Shell Scripting unwanted '?' character at the end of file name

Question

I get an unwanted \'?\' at the end of my file name while doing this:

emplid=$(grep -a \"Student ID\" \"$i\".txt  | sed \'s/(Student ID:  //g\' | sed \'s/)Tj         


        

Answer 1

It sounds like your script file has DOS-style line endings (\r\n) instead of unix-style (just \n) -- when a script in this format, the \r gets treated as part of the commands. In this instance, it's getting included in $emplid and therefore in the filename.

Many platforms support the dos2unix command to convert the file to unix-style line endings. And once it's converted, stick to text editors that support unix-style text files.

EDIT: I had assumed the problem line endings were in the shell script, but it looks like they're in the input file ("$i".txt) instead. You can use dos2unix on the input file to clean it and/or add a cleaning step to the sed command in your script. BTW, you can have a single instance of sed apply several edits with the -e option:

emplid=$(grep -a "Student ID" "$i".txt  | sed '-e s/(Student ID:  //g' -e 's/)Tj//g' -e $'s/\r$//' )

I'd recommend against using sed 's/.$//' -- if the file is in unix format, that'll cut off the last character of the filename.

Answer 2

using the file command to detect if it is pure unix or mixed with DOS.

DOS file: ASCII text, with CRLF line terminators

Unix file is pure ASCII file.