perldoc -f sprintf

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Code: (dl )

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* (minimum) width

Arguments are usually formatted to be only as wide as required to display the given value. You can override 
the width by putting a number here, or get the width from the next argument (with * ) or from a specified 
argument (e.g., with *2$):

    printf "<%s>", "a"; # prints "<a>"
    printf "<%6s>", "a"; # prints "< a>"
    printf "<%*s>", 6, "a"; # prints "< a>"
    printf '<%*2$s>', "a", 6; # prints "< a>"
    printf "<%2s>", "long"; # prints "<long>" (does not truncate)

If a field width obtained through * is negative, it has the same effect as the - flag: left-justification.
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