C Programmer's Guide Part Number: 800-3844-10 Revision A of 27 March, 1990 Trademarks Sun Workstation® is a trademark of Sun Microsystems, Incorporated. SunOS1M is a trademark of Sun Microsystems, Incorporated. Copyright © 1989 Sun Microsystems, Inc. - Printed in U.S.A. All rights reserved. No part of this work covered by copyright hereon may be reproduced in any fonn or by any means - graphic, electronic, or mechanical - including photocopying, recording, taping, or storage in an infonnation retrieval system, without the prior written permission of the copyright owner. Restricted rights legend: use, duplication, or disclosure by the U.S. government is subject to restrictions set forth in subparagraph (c)(I)(ii) of the Rights in Technical Data and Computer Software clause at DFARS 52.227-7013 and in similar clauses in the FAR and NASA FAR Supplement. The Sun Graphical User Interface was developed by Sun Microsystems, Inc. for its users and licensees. Sun ack­ nowledges the pioneering efforts of Xerox in researching and developing the concept of visual or graphical user inter­ faces for the computer industry. Sun holds a non-exclusive license from Xerox to the Xerox Graphical User Interface, which license also covers Sun's licensees. This product is protected by one or more of the following U.S. patents: 4,777,485 4,688,190 4,527,232 4,745,407 4,679,0144,435,7924,719,5694,550,368 in addition to foreign patents and applications pending. • eo: Contents Chapter 1 U sing The Sun C Compiler ...................................................................... 1 1.1. Basics - Compiling and Running C Programs ............................................ 1 1.2. C Compiler .......................................................................................................................... 3 1.3. cc Options ......................................................................................................................... 3 -a Option ........................................................................................................................ 3 -align _block_ Option ...................................................................................... 3 - B binding Option ...................................................................................................... 4 -c Option ........................................................................................................................ 4 -c Option ........................................................................................................................ 4 -dalign Option ....................................................................................................... 4 -dryrun Option ....................................................................................................... 4 - Dname [ =defJ Option .............................................................................................. 4 -E Option ........................................................................................................................ 4 Floating-Point Options .............................................................................................. 4 -g Option ........................................................................................................................ 5 -go Option ..................................................................................................................... 5 -help Option 5 - Ipathname Option ..... ".............. ,. .................................... "........... :..... ;.:;;;;; ... ;;:.;:.," ... ;~:;:.~;;, .... - J Option ........... "............................................... ......................... ;;;;;; .. ,.... i«;' •••• ; •. :;:.:;:;; ••• ;';:;;:;;.",;;.;::' -1 library Option .............. ,. ...................................... ,~~~~"':;.;.,.,:;@.~ ....: ..... ;+~~ ... ;.;.;.;:...•• , •• ,.: ....... ;;<". - L dir Option ................................................................... ·..• :.·.......... ;;,,;.,.,:,;: .. "•. ;'H~~:~.:,,;,~.;;·;;;·;i.,,,,, -MOption .................................................................................... "'....... , .. "... ;" ...... ;........ ~.,~ .. ,,'.>< -misalign Option ...................................................................... ;•• ;;;; .•. ;;:;;;.;., ... ~,.:......... .. 6 -0 output/Lie Option ................................................................................... :••• ;;; ............ .. 6 - iii- Contents - Continued -O[level] ........................................................................................................................... 6 -p Option ........................................................................................................................ 6 -P Option ........................................................................................................................ 6 -pg Option ..................................................................................................................... 6 -pic Option ................................................................................................................. 6 -PIC Option ................................................................................................................. 6 -pipe Option .............................................................................................................. 7 -Qoption prog opt Option ................................................................................ 7 -Qpa th pathnarrze Option .................................................................................. 7 -Qproduce sourcetype Option ........................................................................ 7 -R Option ........................................................................................................................ 7 -8 Option ........................................................................................................................ 7 -sb Option ..................................................................................................................... 7 target_arch Option ...................................................................................................... 7 -t emp= dir Option ................................................................................................... 7 -t ime Option .............................................................................................................. 8 -Uname Option ............................................................................................................ 8 -w Option ........................................................................................................................ 8 1.4. Environment ....................................................................................................................... 8 FLOAT_OPTION ....................................................................................................... 8 Chapter 2 Accessing a Program's Environment ............................................... 9 2.1. Basics - Accessing Command Line Arguments ......................................... 9 2.2. Basics - Accessing Environment Variables .................................................. 10 Accessing Environment Variable Using getenv () ............................ 11 Chapter 3 Processes ................................................................................................................ 13 3.1. The system () Function ......................................................................................... 13 3.2. Low-Level Process Creation - execl () and execv () ................ 13 3.3. Process Control- fork () and wait () .................................................. 15 3.4. Pipes ........................................................................................................................................ 16 Chapter 4 Signals - Interrupts and All That ...................................................... 21 -iv- Contents - Continued Chapter 5 The Standard I/O Library .......................................................................... 27 5.1. The Standard I/O Library ............................................................................................ 27 5.2. Using the Standard I/O Library ............................................................................... 27 5.3. The Standard Input and Standard Output .......................................................... 29 Reading Standard Input and Writing Standard Output ........................... 29 5.4. ErrorHandling- stderrand exit() .................................................... 31 5.5. Miscellaneous 110 Functions .................................................................................... 31 Chapter 6 Accessing Files Through Standard I/O ........................................... 33 6.1. Accessing Files ................................................................................................................. 36 fopen () - Open a File ...................................................................................... 36 freopen () - Reopen a File ........................................................................... 37 fflush () - Flush Stream Buffer ................................................................ 37 fclose () - Close A File ................................................................................. 38 setbuf () - Set Buffer for File I/O ..........................................................