AT&T UNIX Programmers Manual 2ed Jun72 free download

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UNIX PROGRAMMER'S MANUAL Second Edition K. Thompson D. M. Ritchie Jun e 1 2 , 1 972 Copyright @ 1972 Bell Telephone Laboratories, Inc. No part of this document may pe reproduced, _ or distributed outside the Laboratories, without t.he written permission of Bell Telephone Laboratories. PREFACE to the Second Edition In the months since this manual first appeared, many changes have occurred both in the system itself and in the way it is used. Perhaps most obviously, there have been additions, deletions, and modifications to the system and its software. It is these changes, of course, that caused the appearance of this revised manual. Second, the number of pe::>ple spending an appreciabl e amount of time writing UNIX software has increased. Credit is due to L. L. Cherry, M. D. McIlroy, L. E. McMahon, R. Morris, and J. F. Ossanna for their contributions. Finally, the number of UNIX installations has grown to 10, with more expected. None of these has exactly the same complement of hardware or software. Therefore, at any particular installation, it is quite possible that this manual will give inappropriate information. One area to watch concerns commands which deal with special files (I/O devices). Another is places which talk about such things as absolute core locations which are likely to vary with the memory configuration and existence of protection hardware. Also, not all installations have the latest versions of all the software. In particular, the assembler and loader have just undergone major reorganizations in anticipation of a UNIX for the PDP-11/45. - ii - INTRODUCT ION This manual gives descriptions of the publicly available features of UNIX. It provides neither a general overview (see "The UNIX Time-sharing system" for that) nor details of the implementation of the system (which remain to be disclosed). Within the area it surveys, this manual attempts to be as com- pI ete and timely as possibl e. A conscious decision was made to describe each program in exactly the state it was in at the time its manual section was prepared. In particular, the desire to describe something as it should be, not as it is, was resisted. Inevitably, this mea"ns that many sections will soon be out of date. (The rate of change of the system is so great that a dismayingly large number of early sections had to be modified while the rest were being written. The unbounded effort required to stay up-to-date is best indicated by the fact that several of the programs described were written specifically to aid in preparation of this manual!) This manual is divided into seven sections: I. ():)mmands II. System calls III. SUbroutines N. Special files V. File formats VI. User-maintained programs VII. Miscellaneous