Pattern Matching Details, Environment Variables, and Diagnostics

‐RE option to avoid the confusion that names with [ or ] have caused. When these characters are encountered (without being escaped with a backslash or quotes), the shell will look for files relative to the cur‐ rent path that match the pattern, and replace the argument with a list of the names that matched. The zip program can do the same matching on names that are in the zip archive being modified or, in the case of the -x (exclude) or -i (in‐ clude) options, on the list of files to be operated on, by using back‐ slashes or quotes to tell the shell not to do the name expansion. In general, when zip encounters a name in the list of files to do, it first looks for the name in the file system. If it finds it, it then adds it to the list of files to do. If it does not find it, it looks for the name in the zip archive being modified (if it exists), using the pattern matching characters described above, if present. For each match, it will add that name to the list of files to be processed, unless this name matches one given with the -x option, or does not match any name given with the -i option. The pattern matching includes the path, and so patterns like \*.o match names that end in ".o", no matter what the path prefix is. Note that the backslash must precede every special character (i.e. ?*[]), or the entire argument must be enclosed in double quotes (""). In general, use backslashes or double quotes for paths that have wild‐ cards to make zip do the pattern matching for file paths, and always for paths and strings that have spaces or wildcards for -i, -x, -R, -d, and -U and anywhere zip needs to process the wildcards. ENVIRONMENT The following environment variables are read and used by zip as de‐ scribed. ZIPOPT contains default options that will be used when running zip. The contents of this environment variable will get added to the com‐ mand line just after the zip command. ZIP [Not on RISC OS and VMS] see ZIPOPT Zip$Options [RISC OS] see ZIPOPT Zip$Exts [RISC OS] contains extensions separated by a : that will cause native filenames with one of the specified extensions to be added to the zip file with basename and extension swapped. ZIP_OPTS [VMS] see ZIPOPT SEE ALSO compress(1), shar(1), tar(1), unzip(1), gzip(1) DIAGNOSTICS The exit status (or error level) approximates the exit codes defined by PKWARE and takes on the following values, except under VMS: 0 normal; no errors or warnings detected. 2 unexpected end of zip file. 3 a generic error in the zipfile format was detected. Pro‐ cessing may have completed successfully anyway; some bro‐ ken zipfiles created by other archivers have simple work‐ arounds. 4 zip was unable to allocate memory for one or more buffers during program initialization. 5 a severe error in the zipfile format was detected. Pro‐ cessing probably failed immediately. 6 entry too large to be processed (such as input files larger than 2 GB when not using Zip64 or trying to read an existing archive that is too large) or entry too large to be split with zipsplit 7 invalid comment format 8 zip ‐T failed or out of memory 9 the user aborted zip prematurely with control‐C (or simi‐ lar)

This section delves into the details of pattern matching with zip, explaining how zip uses backslashes or quotes to prevent the shell from doing name expansion, allowing zip to find files in the file system or the zip archive. It then discusses environment variables such as ZIPOPT, ZIP, Zip$Options, Zip$Exts, and ZIP_OPTS that affect zip's behavior. Finally, it lists the diagnostic exit status codes returned by zip, indicating the success or failure of the operation and the type of errors encountered.