This manual page is not meant to be exhaustive. The complete documentation for this version of TEX can be found in the info file or manual Web2C: A TeX implementation.
The vftovp program translates a (program-oriented) virtual font file and its accompanying TEX font metric file to a (human-oriented) property list file. Thus, the virtual font can be edited, and its exact contents can be displayed mnemonically. It also serves as a VF-file validating program; if no error messages are given, the input files are correct.
The argument format to -charcode-format specifies how character codes are output in the VPL file. By default, only letters and digits are output using the C integer code (i.e., in ASCII); the others are output in octal. (Unless the font's coding scheme starts with TeX math sy or TeX math ex, when all are output in octal.) If format is ascii, all character codes that correspond to graphic characters, besides the left and right parentheses, are output in ASCII. On the other hand, if format is octal, all character codes are output in octal.
vftovp looks for vf_name using the environment variable VFFONTS. If that is not set, it uses the variable TEXFONTS. If that is not set, it uses the system default.