Shell read script for sftp

Question

I have this working:

% cat read.sh
!/bin/sh

file=list.txt

while read line
do
    echo "$line"
cut -d' ' -f27 | sed -n '$p' > file2
done < "$file"


% cat list.txt 
sftp> #!/bin/sh
sftp> 
sftp> cd u/aaa
sftp> ls -lrt x_*.csv
-rwxr-xr-x    0 1001     1001     12274972 May 13 21:07 x_20150501.csv
-rw-r--r--    0 1001     1001            0 May 13 21:44 x_20150601.csv
-rw-r--r--    0 1001     1001            0 May 13 21:44 x_20150701.csv
-rw-r--r--    0 1001     1001            0 May 13 21:44 x_20150801.csv
-rw-r--r--    0 1001     1001            0 May 13 21:44 x_20150901.csv
-rw-r--r--    0 1001     1001            0 May 13 21:45 x_20151001.csv
-rw-r--r--    0 1001     1001            0 May 13 21:45 x_20151101.csv
-rw-r--r--    0 1001     1001            0 May 13 21:45 x_20151201.csv

% cat file2 
x_20151201.csv

First question: Is there something more glamorous to read just the very last item on the very last line? Would you use cut and sed? This is a redirect of a sftp directoy listing.

Second question: Whatever is in file2, I want to have it read from a sftp batch file to get that exact file.

% cat fetch.sh 
#!/bin/sh

cd u/aaa
!sh read.sh
!< file2 
get
bye

As you can imagine, sftp doesn't like get provided without any file, so how can I read in file2 to get that file from the sftp server?

 % sftp -b fetch.sh user@pulse
    sftp> #!/bin/sh
    sftp> 
    sftp> cd u/aaa        
    sftp> !sh read.sh
    sftp> #!/bin/sh
    sftp> !< file2 
    x_20151201.csv
    sftp> get
    You must specify at least one path after a get command.

Answer 1

You can combine all the actions in one command:

sftp user@host:/path/to/file/$(tail -1 file1.txt |tr -s ' ' |cut -d ' ' -f 9)

This will fetch the file into the current working directory. If you need to fetch the file into another directory specify the destination directory as a next argument to the sftp command.