.fin .all A list consists of a series of names, words, numbers, or groupings of items. List processing involves placing the items (data records) in a list in order, and sorting, adding, discarding or selecting items from the list. List processing uses three types of files: a listin file, a lister file, and a listform file. The listin file is used to enter and update a list with a text editor. It contains a header that defines the parts of the records as they appear in the listin file, and it contains the individual records that make up the list. For example, the following are two records in a doctor's list of patients: .fif Record_delimiter: $; Field_delimiter: =; Field_names: lname,fname,street,city,state,zip Records: $ =lname Doe =fname John =street 17 Oak St. =city Boston =state Massachusetts =zip 12112 $ =lname Smith =fname Jane =street 898 Linden Way =city Cambridge =state Massachusetts =zip 02139 .fin The record delimiter separates records from each other, and the field delimiter marks the beginning of a field name. The listin file must have a name that ends with the suffix '.listin'. A lister file contains a list in a form that can be processed. Once you've constructed a listin file, you convert it to a lister file with the create_list command. This command takes the name of the new lister file as its "pathname" "argument". For example: create_list patients.lister The command creates the lister file from the listin file with the same name. The only difference between the names is the final suffixes--'.listin' and '.lister'. In order to process a list, you need a listform file to specify how the list will appear when printed. As an example, let's assume the doctor wants an organized list of her patients and their addresses. She would use a text editor to construct a listform file like the following: .fif Patient Addresses , Medical Associates .fin The 'before' and 'after' sections contain information that will appear only once with the entire list, not with each record. A list form does not have to contain all the fields in the records of a lister file to be usable with that file. In fact, a single lister file can be processed with different listform files to produce a variety of formats for the records. Lister files are processed with the process_list command. This command takes two pathname arguments, one for the lister file and one for the listform. For example: process_list patients.lister addresses.listform The suffixes '.lister' and '.listform' must be on the names of the respective files, but they need not be supplied on the command line as they are in this example. There are three important "control arguments" that are often needed with the process_list command: -select, -sort, and -output_file. The -select control argument enables you to select certain records for processing. It consists of three parts: the field name, a comparison operator, and a test string. The comparison operator specifies what comparison is to be performed. The operators are: 'contains,' 'not contains,' 'equal,' 'not equal,' 'greater,' 'not greater,' 'less,' and 'not less.' The test string is the value to which the field name is compared. For example, to list all the patients whose last names begin with 'S', type: process_list patients addresses -select "lname equal S" The -sort control argument is used to change the order in which the list is processed. For example, if you type: process_list patients addresses -sort lname the records in patients.lister will be processed in alphabetical order by last name. Finally, the -output_file control argument is used to place the processed list into a "segment" which can then be printed out on some form of printer. For example, if you were putting the names in patients.lister into the format of a letter, then you would probably want to print the results out on letterhead in a high-quality wordprocessing printer. To do that you would first have to store the processed information in a segment. There are other useful list processing procedures documented in the Guide to Multics WORDPRO for New Users (Order No. DJ18) and the Multics WORDPRO Reference Guide (AZ98). ----------------------------------------------------------- Historical Background This edition of the Multics software materials and documentation is provided and donated to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. as a contribution to computer science knowledge. This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology, Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL and BULL HN Information Systems Inc. to the development of this operating system. Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970), renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture for managing computer hardware properly and for executing programs. Many subsequent operating systems incorporated Multics principles. Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. . ----------------------------------------------------------- Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without fee is hereby granted,provided that the below copyright notice and historical background appear in all copies and that both the copyright notice and historical background and this permission notice appear in supporting documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining to distribution of the programs without specific prior written permission. Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc. Copyright 2006 by BULL HN Information Systems Inc. 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