JSch ChannelSftp.ls - pass match patterns in java

Question

I have multiple files at an sftp location like

xyz_20140101.csv.gz
xyz_2014_01_01.csv.gz
xyz_20140202.csv.gz
xyz_2014_02_02.csv.gz

through my java program i want to get list of files only in format xyz_YYYYMMDD.csv.gz , what should be my match pattern to pass in ChannelSftp.ls command .

I am passing

pattern = xyz_*csv.gz , but it gives me all the files .

ChannelSftp.ls(pattern);

What should be my pattern to pass in ls command ?

Answer 1

ChannelSftp.ls takes as argument a path: http://epaul.github.io/jsch-documentation/javadoc/com/jcraft/jsch/ChannelSftp.html#ls(java.lang.String)

the path can contain glob pattern wildcards (* or ?) but with this you are not able to check that date has digits in it.

so just list the path and apply regex after

        Vector ls = channelSftp.ls(path);
        Pattern pattern = Pattern.compile("xyz_[0-9]{8}.csv.gz");
        for (Object entry : ls) {
            ChannelSftp.LsEntry e = (ChannelSftp.LsEntry) entry;
            //match regex on e.getFilename()
            Matcher m = pattern.matcher(e.getFilename());
            if (m.matches()) {
                //TODO you code
            }

        }

in case you don't need to check that date is formatted from digits you can just use following pattern and ChannelSftp.ls

pattern =  xyz_????????.csv.gz

but this will also match something like: xyz_2014_aaa.csv.gz

Answer 2

The ChannelSftp.ls accepts path AND pattern in its path argument:

Parameters:

path - a pattern relative to the current remote directory. The pattern can contain glob pattern wildcards (* or ?) in the last component (i.e. after the last /).

You should include a path to the directory to the argument; and modify the pattern to match only the files you need. The pattern you are using indeed matches any file on your list, not only the files you want.

You can use xyz_????????.csv.gz to explicitly require the variable part to have 8 characters.

path_and_pattern = "/path/xyz_????????.csv.gz";

files = channel.ls(path_and_pattern);