I have a bash script
OLDIFS=$IFS
echo "Debugging: $1"
IFS=' '
frst=true
EXECPATH=$(file $1 | sed -r "s/^.*execfn: '([^']*)'.*$/\1/")
while read x id path x exec
do
if [ $frst = true ];then
frst=false
path=$exec
fi
.
.
Can someone explain what while read x id path x exec is? I know read reads the output and assign it to variables but why do I have two x?
Script is being called like ./myScrpt.sh 'ls filename'
Note that x is never used; it's just a dummy variable to capture fields you don't care about, so that the field splitting performed by read assigns the desired values to id, path, and exec.
_ is more commonly used as such a dummy. Also, it's better to simply override the value of IFS just for the read command than to override it globally and (attempt to) restore its value later.
echo "Debugging: $1"
frst=true
EXECPATH=$(file "$1" | sed -r "s/^.*execfn: '([^']*)'.*$/\1/")
while IFS=' ' read _ id path _ exec
do
if [ "$frst" = true ];then
frst=false
path=$exec
fi
.
.
while is; the rest of the loop probably looks something like while read ...; do ...; done <<< "$EXECPATH" (I'm assuming that the output of the pipeline is what is being parsed.)
while what would it read? For ex. here(askubuntu.com/questions/604626/…) it is reading from echo and how many time while loop with read will run? infinite times?echo produces a single line of output, which the first call to read consumes entirely.$1 to expand to multiple words (generally a bad idea; use "$@" instead of $1, and change the call to ./myScrpt.sh ls filename). In that case, file will produce multiple lines of output, and so the while loop will process each line one at a time.id path and exec?