fcnvt(1) fcnvt(1)NAME fcnvt - converts a file in one storage format to a different storage format SYNOPSIS fcnvt [-f] [-v] [-i start-format] -s input-file output-file fcnvt [-f] [-v] [-i start-format] -d input-file output-file fcnvt [-f] [-v] [-i start-format] -t input-file output-file fcnvt [-f] [-v] [-i start-format] -p input-file output-file fcnvt [-f] [-v] [-i start-format] -b input-file output-file fcnvt [-f] [-v] [-i start-format] -m input-file output-file ARGUMENTS -b Converts the input file to BinHex 4.0 format. The input file is encoded into ASCII characters, permitting ASCII transfer of a binary file. -d Converts the input file to Apple Double format. -f Allows fcnvt to overwrite an existing file with the same name as the new file. -i start-format Specifies the current format of the file to be converted. If an input-file format is not specified in this way, the Apple Single format is assumed. input-file Specifies the file to be converted. -m Converts the input file to a MacBinary format. This format is commonly used to transfer Macintosh files by means of a telecommunications link, using a protocol such as XMODEM, XMODEM7, Kermit, CompuServe A, or CompuServe B. output-file Specifies the name of the file to be created in the desired storage format. -p Converts the input file to Plain Pair format. This option is the same as the -t option except that output-file.info is not created. -s Converts the input file to Apple Single format. This format is the default. January 1992 1
fcnvt(1) fcnvt(1)start-format Specifies the present format of the file to be converted, in terms of one of the following formats: single double triple pair bin hex These values correspond to the Apple Single, Apple Double, Plain Triple, Plain Pair, BinHex 4.0, and MacBinary formats as explained in ``File Formats'' in the ``Description'' section. -t Converts the input file to Plain Triple format. Three files are created; suffixes are used to distinguish the three derived files. (See ``File Formats'' in the ``Description'' section.) -v Specifies verbose mode. In verbose mode, fcvnt displays information as it processes each file. DESCRIPTION fcnvt converts a file in one storage format to a corresponding file in a different storage format. The Finder application fully supports only the Apple Double and Apple Single formats; that is, you can open files in either of these two formats by double-clicking or by choosing Open from the File menu of the Finder. The main purpose of fcnvt is to convert Macintosh files received in a foreign format to one of the native formats of Apple Single or Apple Double. File formats other than the genuine Apple Double and Apple Single formats are needed because the native file formats permit files to contain data values that make electronic transmission unreliable. Even with the best communications programs, files containing all the possible binary data values can cause transmission problems. Therefore, a conversion process is the only really safe method for transmitting files. The Macintosh Operating System takes advantage of a twin- file storage scheme. Whenever applicable, certain types of data are stored in a resource-fork file as well as a data- fork file. For users, this fact is normally irrelevant because the Finder represents these twin files with a single icon, and both files are manipulated simultaneously as if 2 January 1992
fcnvt(1) fcnvt(1)they were one file. File Formats Of the file formats that can be obtained, the most desirable ending format is a Finder-compatible one. The Finder can decipher and open files in Apple Single and Apple Double file formats only. With Apple Single (single) format, data and file-attribute information is kept in a single file. Apple Single format is best used for nontext data and executable Macintosh object files. Directory listings look much cleaner because each Macintosh file is mapped to a single A/UX file with no percent sign (%) prefix. A header at the beginning of the file contains offsets to the data, resource information, or both, as well as information corresponding to Macintosh file attributes. With Apple Double (double) format, the contents of the data fork are stored in one file, known as the data file; resources and file-attribute information are stored in a separate file, known as the header file. The header file has the same name as the data file, but the filename is prefixed with a percent sign. The Apple Double format is best used for text data and data to be shared with UNIX utilities, because the data fork is available as an isolated file. The Plain Triple (triple) format is used by the macget and macput public-domain file-transfer programs. The files output-file.info, output-file.data, and output-file.rsrc contain identification information, the data fork, and the resource fork, respectively. The Plain Pair (pair) format is similar to the triple format except that output-file.info is not created. The BinHex 40 format converts all binary and any other data into an ASCII-encoded form, permitting an ASCII transfer mode for what were once binary files. The MacBinary storage format is commonly used to transfer Macintosh files over a telecommunications link, using a protocol that supports certain kinds of binary file transfers, such as XMODEM, XMODEM7, Kermit, CompuServe A, or CompuServe B. File Transfers Among UNIX users, files are often distributed electronically, and often they are compressed as well as converted into easily transmittable formats. To recover the transmitted file to a form that is usable, the expansion and conversion steps must be performed in the reverse order in January 1992 3
fcnvt(1) fcnvt(1)which these steps were performed before transmission. To illustrate the simpler case (no file compression before transmission), you could make the file /FileMakerII ready for transmission by converting it to a MacBinary format with fcnvt -m /FileMakerII /tmp/filemaker Once received by the receiving party, the file can be converted back to an Apple Single format with this command: fcnvt -i bin filemaker.bin FileMakerII A MacBinary format is commonly used to send Macintosh files over a telecommunications link using a protocol such as XMODEM, XMODEM7, Kermit, CompuServe A, or CompuServe B. A file downloaded onto your system through a terminal emulator program is likely to be in text-only format, BinHex 4.0 format, or MacBinary format, or it may simply be a copy of the resource fork of the Macintosh file. The preferred way to discover the format is to receive that information directly from the sender. Note that file transfers made through terminal emulators are likely to strip away the Macintosh type and creator attributes for the file. (Each of these attributes is one four-character string.) See setfile(1) for information on restoring these attributes. If they are missing, the preferred way to discover these attributes is to receive that information directly from the sender. FILES /mac/bin/fcnvt Executable file SEE ALSO setfile(1), tar(1), uuencode(1C), uusend(1C) 4 January 1992