Perldoc Search: "$~" perl-5.20.1
search official POD
3 PODs, 6 LINEs found.
146 : The current format name is stored in the variable $~ ($FORMAT_NAME), and the current top of form format name is in $^ ($FORMAT_TOP_NAME). The current output page number is stored in $% ($FORMAT_PAGE_NUMBER), and the number of lines on the page is in $= ($FORMAT_LINES_PER_PAGE). Whether to autoflush output on this handle is stored in $| ($OUTPUT_AUTOFLUSH). The string output before each top of page (except the first) is stored in $^L ($FORMAT_FORMFEED). These variables are set on a per-filehandle basis, so you'll need to select() into a different one to affect them:
149 : $~ = "My_Other_Format",
156 : $~ = "My_Other_Format";
1167 : $~ = 'Something';
4884 : Writes a formatted record (possibly multi-line) to the specified FILEHANDLE, using the format associated with that file. By default the format for a file is the one having the same name as the filehandle, but the format for the current output channel (see the "select" function) may be set explicitly by assigning the name of the format to the $~ variable.
815 : $~ The name of the current report format for the currently selected output channel. The default format name is the same as the filehandle name. For example, the default format name for the "STDOUT" filehandle is just "STDOUT".