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Full Discussion: Please explain this
Top Forums Shell Programming and Scripting Please explain this Post 302493384 by methyl on Wednesday 2nd of February 2011 02:09:32 PM
Old 02-02-2011
There are several problems with the line posted. We really need to see it in the context of the whole script and with a description of what the script is meant to do.

To answer one of your questions.
If there is a variable called $i which needs to be substituted into svucon$i_bal_dup_email.dat it will not work. This is because underscore is a valid character in a variable name.

Here is an example of what can happen. Note the use of braces to show shell where the variable name ends.
Code:
i=abc
echo First attempt  : $i_string
echo Second attempt : ${i}_string

First attempt :
Second attempt : abc_string

On the second point. The semi-colon is just allowing you to place two unrelated commands on the same line. It may be wrong.
The second command converts a file $dup_in to "uuencode" format outputting to $dup_out . There is no input from the preceding command.
The normal use of "uuencode" is to prepare a file to be an email attachment.
 

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uuencode(4)						     Kernel Interfaces Manual						       uuencode(4)

NAME
uuencode - format of an encoded uuencode file DESCRIPTION
Files output by consist of a header line followed by a number of body lines, and a trailer line. The command ignores any lines preceding the header or following the trailer (see uuencode(1)). Lines preceding a header must not look like a header. The header line consists of the word followed by a space, a mode (in octal), another space, and a string which specifies the name of the remote file. The body consists of a number of lines, each containing 62 or fewer characters (including trailing new-line). These lines consist of a character count, followed by encoded characters, followed by a newline. The character count is a single printing character, which represents an integer. This integer is the number of bytes in the rest of the line, and always ranges from 0 to 63. The byte count can be determined by subtracting the equivalent octal value of an ASCII space charac- ter (octal 40) from the character. Groups of 3 bytes are stored in 4 characters, 6 bits per character. All are offset by a space to make the characters printable. The last line may be shorter than the normal 45 bytes. If the size is not a multiple of 3, this fact can be determined by the value of the count on the last line. Extra meaningless data will be included, if necessary, to make the character count a multiple of 4. The body is terminated by a line with a count of zero. This line consists of one ASCII space. The trailer line consists of the word on a line by itself. SEE ALSO
mail(1), uuencode(1), uucp(1). uuencode(4)
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