How to create a file of specific size on sd card programatically

Question

Can some one please let me know how to create a file of specific size on sd card programatically. I did tried shell command like this which is of no use,

try {
   Process p = Runtime.getRuntime().exec("dd of=/mnt/extSdCard/output.dat bs=1 seek=1M count=0");
} catch (IOException e1) {

}

I did even try the same command in shell script and was not able to create the file. I guess since my device is not rooted, this command did not work.

Any help regarding this highly appreciated.

-regards, Manju

check out this post: http://stackoverflow.com/questions/9252332/android-pre-allocate-space-for-a-file-before-downloading-it — android developer, Jul 11 '13 at 05:20
Hi android developer, Thanks for the info and that worked for me. Pls let me know how to accept your answer — Manju, Jul 11 '13 at 10:44
i will now create a new answer that you will be able to tick as answered. — android developer, Jul 11 '13 at 12:30

score 1 · Accepted Answer · edited May 23 '17 at 12:11

1

you can use RandomAccessFile as shown here.

edited May 23 '17 at 12:11

Community

1
1

answered Jul 11 '13 at 12:31

android developer

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score 0 · Answer 2 · answered Jul 11 '13 at 06:33

First you obtain prermission for External storage. Edit the AndroidManifest.xml with the following line of code.

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

After that in java file write the following code. File fileName = new File(Environment.getExternalStorageDirectory(), "output.dat"); FileOutputStream fos = new FileOutputStream(fileName ) fos.write(bytes);

How to create a file of specific size on sd card programatically

2 Answers2