I am using the following command to email a tex file as an attachment-

cat mailtext.txt | elm -s "Subject" emailAddr
where content of mailtext.txt is -
"Body of email"
[include foo.txt text/plain base64]

This will attach foo.txt with the email.

My problem is that the file foo.txt is ceated dynamically everytime with a timestamp. e.g. foo_<timestamp>.txt

So if this filename is collected in a variable-
sFileName = foo_<timestamp>.txt

How do I include this filename dynamically in the mailtext.txt file?

Any help would be appreciated.

Thanks.

Use a HERE document and interpolate the value of a variable containing the file name.

elm -s "Subject" emailAddr <<HERE
"Body of email"
[include $sFileName text/plain base64]
HERE

Thanks for the solution ...

I am providing this command in a C program.

sprintf( cmd, "elm -s SUBJECT %s <<HERE \n %s \n [include %s text/plain base64] \n HERE ", emailAddr, sMailBody, sFileName );

This is sending the [include %s text/plain base64] part also in the email body along with the actual body text. And there is no file attached in the email.

Could you please help me with this ???

The <<HERE is a feature of the shell; you need to spawn a shell to get it working.

sprintf (cmd, "sh -c 'elm -s SUBJECT %s <<HERE\n"
  "%s\n[include %s text/plain base64]\nHERE\n'"l, emailAddr, sMailBody, sFileName);

Could you please explain me how to use popen() ?

It could be a pretty simple thing, but I m a novice in unix. It would be good if you could show me the command.

Googling for "popen examples" gets me e.g. popen