Question

I am trying to do a bash script that:

• loop over some files : OK
• check if the first line matches this pattern (#!f:\test\python.exe) : OK
• create a new path by changing the unix style to windows style : KO

Precisely,
From: \c\tata\development\tools\virtualenvs\test2\Scripts\python.exe
I want to get: c:\tata\development\tools\virtualenvs\test2\Scripts\python.exe

• insert the new line by appending #! and the new path : KO

Follow is my script but I’m really stuck!

for f in $WORKON_HOME/$env_name/$VIRTUALENVWRAPPER_ENV_BIN_DIR/*.py
    do
        echo "----"
        echo file=$f >&2

        FIRSTLINE=`head -n 1 $f`        
        echo firstline=$FIRSTLINE >&2

        unix_path=$WORKON_HOME/$env_name/$VIRTUALENVWRAPPER_ENV_BIN_DIR/python.exe
        new_path=`echo $unix_path | awk '{gsub("/","\\\")}1'`       
        echo new_path=$new_path >&2

        # I need to change the new_path by removing the first \ and adding : after the first letter => \c -> c:

        new_line="#!"$new_path
        echo new_line=$new_line >&2

        case "$FIRSTLINE" in 
         \#!*python.exe* )
            # Rewrite first line
            sed -i '1s,.*,'"$new_line"',' $f
        esac        
    done

Output:

file=/c/tata/development/tools/virtualenvs/test2/Scripts/pip-script.py
firstline=#!f:\test\python.exe
new_path=\c\tata\development\tools\virtualenvs\test2\Scripts\python.exe
new_line=#!\c\tata\development\tools\virtualenvs\test2\Scripts\python.exe

Line that is written in the file: (some weird characters are written I do not know why…)

#!tatadevelopment   oolsirtualenvs  est2Scriptspython.exe

Line I am expecting:

#!c:\tata\development\tools\virtualenvs\test2\Scripts\python.exe

Answer 1

sed is interpreting the backslashes and characters following them as escapes, so you’re getting, e.g. tab. You need to escape the backslashes.

sed -i "1s,.*,${new_line//\\/\\\\}," "$f"