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Diffstat (limited to 'doc/odb-epilogue.1')
| -rw-r--r-- | doc/odb-epilogue.1 | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/doc/odb-epilogue.1 b/doc/odb-epilogue.1 index c2dbd05..b202796 100644 --- a/doc/odb-epilogue.1 +++ b/doc/odb-epilogue.1 @@ -1,4 +1,28 @@ .\" +.\" REGEX AND SHELL QUOTING +.\" +.SH REGEX AND SHELL QUOTING +When entering a regular expression argument in the shell command line +it is often necessary to use quoting (enclosing the argument in " " +or ' ') in order to prevent the shell from interpreting certain +characters, for example, spaces as argument separators and $ as +variable expansions. + +Unfortunately it is hard to achieve this in a manner that is portable +across POSIX shells, such as those found on GNU/Linux and UNIX, and +Windows shell. For example, if you use " " for quoting you will get +a wrong result with POSIX shells if your expression contains $. The +standard way of dealing with this on POSIX systems is to use ' ' +instead. Unfortunately, Windows shell does not remove ' ' from +arguments when they are passed to applications. As a result you may +have to use ' ' for POSIX and " " for Windows ($ is not treated as +a special character on Windows). + +Alternatively, you can save regular expression options into a file, +one option per line, and use this file with the +.B --options-file +option. With this approach you don't need to worry about shell quoting. +.\" .\" DIAGNOSTICS .\" .SH DIAGNOSTICS |