Loop in text files shell script

Question

I have a list of files in one directory and a set of jpegs corresponding to each file in another directory. I need to loop over all files, and for each file name, determine the target directory.

For example, if I have three text files called foo.txt, bar.txt and baz.txt in /home/userA/folder/, the corresponding jpegs will be in /home/userA/folder2/foo/, /home/userA/folder2/bar/ and /home/userA/folder2/baz/.

I wrote a script that should loop over all txt files and get the corresponding target directories but it's giving me an error:

bash: /home/userA/folder/File1.txt: syntax error: operand expected (error token is "/home/userA/folder/File1.txt")`

My script:

#!/bin/bash
FILES=/home/userA/folder/*.txt
for i in $FILES
do
    str1=$i | cut -d'/' -f5 #to get the name of the file
    echo /home/userA/folder2/$i_filename #I want to include the .txt filename in the output to be like this /home/userA/folder2/Text1_filename    
done

How can I fix this?

Answer 1

If all you want is to get the file's name and use it to get the right target directory, you can do:

#!/bin/bash
for i in /home/userA/folder/*.txt
do
    ## Get the file name
    str1="${i##*/}"

    ## Get the target directory
    dir="/home/userA/folder2/${str1%.txt}/"
done

This is using the shell's native string manipulation features. ${var##pattern} removes the longest match of pattern from the start of $var and ${var%pattern} removes the shortest match of pattern from the end of $var. So, ${i##*/} removes everything until the last / (the path) from the file name and ${i%.txt} removes the string .txt from the end of it.

Answer 2

You just forget the echo and backquotes and field number on this line

    str1=`echo $i | cut -d'/' -f5 `#to get the name of the file

But basename might be a better option.

    str1=`basename $i` #name of the file

Like this

#!/bin/bash
FILES=/home/userA/folder/*.txt
for i in $FILES
do
    str1=`basename "$i"` #to get the name of the file
    echo $str1
    ls -l "`dirname "$i"`/$str1"
done

For a good answer about dealing with for loops and files with spaces in their name refer to This answer

Answer 3

Using find:

#!/bin/bash
path="/home/userA/folder"
find "$path" -maxdepth 1 -type f -name "*.txt" -print0 | while read -d $'\0' file; do
    a="$path/$(basename $file)/a_%06.jpg"
    echo "$a
done

Answer 4

Do you mean this?

 ~/test $ for i in F/*.txt; do n="TARGET/$(basename "$i" .txt)"; echo "$n"; done
TARGET/a
TARGET/b
TARGET/c
 ~/test $ ls F
a.txt  b.txt  c.txt
 ~/test $

And with special chars and spaces:

 ~/test $ for i in F/*.txt; do n="TARGET/$(basename "$i" .txt)"; echo "\"$n\""; done
"TARGET/a b€C\""
"TARGET/a"
"TARGET/b"
"TARGET/c"
 ~/test $ ls F
a b€C\".txt  a.txt  b.txt  c.txt

Answer 5

find /home/userA/folder/ -maxdepth 1 -type f -name "*.txt" -print0 | while read -r -d '' file; do filename=$(printf "%s\n" "$file" | awk -F'/' '{gsub(".txt","");print $5}' ); printf "/home/userA/folder2/%s" "$filename"; done

Answer 6

If you really want to put it in a variable, you can use a bash array:

#!/bin/bash
FILES=(/home/userA/folder/*.txt)
for i in "${FILES[@]}" # double qouting pervents extra word splitting
do
    bn="$(basename "$i")" # to get the name of the file
    a="/home/userA/folder2/$bn/a_%06d.jpg"
done

Or you can simply use for i in /home/userA/folder/*.txt.