CODEWITHSUNDEEP
bashunixshellfilejava
Vinothkumar
Vinothkumar

Reputation:

Unix: “ls” command shows files with ? after the extension

I have written a shell script (test.sh) using Java. This shell script actually does a copy job from one file to the other. After the execution of the shell script I have opened the directory from Console and typed ls. It shows the output file with ? after the extension.

example : foo.csv?

File execFile = new File(file);
FileWriter fwFile;
try {
    fwFile = new FileWriter(execFile);
    execFile.setExecutable(true);
    BufferedWriter bwFile = new BufferedWriter(fwFile);
    bwFile.write(strOutput.substring(0, 2));
    bwFile.write("\r\n");
    bwFile.write("cd " + strOutput);
    bwFile.write("\r\n");
    bwFile.write("mkdir " + strOutput);
    bwFile.write("\r\n");
    bwFile.write(strUnixPath);
    bwFile.write("\r\n");
    bwFile.write("cd " + strWorkingPath + IPlatinumConstants.FS+"lib"+IPlatinumConstants.FS+"Unx");
    bwFile.write("\r\n");
    bwFile.write("echo Cut Src Start time %time%");
    bwFile.write("\r\n");

            bwFile.write("cp " + " \"" + strSourceFilePath + "\"  \""
                    + strOutput + "copy_A\"");
            bwFile.write("\r\n");

Upvotes: 5

Views: 2099

Answers (1)

grawity_u1686
grawity_u1686

Reputation: 16532

My guess:

Your Java program is using \r\n, carriage return + line feed, to terminate each line. However, Unix systems use only the line feed \n as a new-line indicator. While the carriage return is understood by terminals, it has no meaning at all to other programs – it's just a character like any other as far as the /bin/sh interpreter is concerned. This means that the \r becomes part of the last parameter of each command that your script runs:

cd myoutput\r
mkdir myoutput\r
cd something/lib/something\r
echo Cut Src Start time %time%\r
cp "sourcefile" "myoutputcopy_A"\r

So the last command is always creating files that have the carriage-return at the end of their name, and ls shows them as a question mark like all other "unprintable" characters. You can see this using ls -b or ls -Q.

To fix this, use only \n when generating Unix shell scripts. (Or, even better, don't generate shell scripts – instead, write scripts that accept parameters where needed. You could do many things in the Java program itself, as well.)

Upvotes: 13

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