không tìm thấy" về lỗi tiêu chuẩn. # # Các mã thoát là 0 nếu tất cả các tập tin được tìm thấy, và nếu không giá trị bằng số lượng các tập tin không tìm thấy (chủ đề # để hạn chế vỏ mã xuất cảnh 125) # khác không. # # Cách sử dụng: pathfind ] [phiên bản] envvar mô hình | Simpo PDF Merge and Split Unregistered Version - http . Records and Fields Each iteration of the implicit loop over the input files in awk s programming model processes a single record typically a line of text. Records are further divided into smaller strings called fields. . Record Separators Although records are normally text lines separated by newline characters awk allows more generality through the record-separator built-in variable RS. In traditional and POSIX awk RS must be either a single literal character such as newline its default value or an empty string. The latter is treated specially records are then paragraphs separated by one or more blank lines and empty lines at the start or end of a file are ignored. Fields are then separated by newlines or whatever FS is set to. gawk and mawk provide an important extension RS may be a regular expression provided that it is longer than a single character. Thus RS matches a literal plus whereas RS matches one or more colons. This provides much more powerful record specification which we exploit in some of the examples in Section . With a regular expression record separator the text that matches the separator can no longer be determined from the value of RS. gawk provides it as a language extension in the built-in variable RT but mawk does not. Without the extension of RS to regular expressions it can be hard to simulate regular expressions as record separators if they can match across line boundaries because most Unix text processing tools deal with a line at a time. Sometimes you can use tr to convert newline into an otherwise unused character making the data stream one giant line. However that often runs afoul of buffer-size limits in other tools. gawk mawk and emacs are unusual in freeing you from the limiting view of line-oriented data. . Field Separators Fields are separated from each other by strings that match the current value of the field-separator regular expression .
