Obtaining an HP-UX file descriptor

number. For example, the following open system call (called from a C-language program) opens a file named DATA.DAT for reading and writing, and returns the value of an HP-UX file descriptor:

#include /* definition of O_RDWR contained here */

fildes = open("DATA.DAT", O_RDWR)

The Fortran intrinsic FNUMreturns the HP-UX file descriptor for a given logical unit. See the program in “File handling” (page 120) for an example of how to call the FNUMintrinsic. For information about FNUM, see the HP Fortran Programmer's Reference.

Using HP-UX file I/O 109

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HP UX Fortran Software manual Obtaining an HP-UX file descriptor, Using HP-UX file I/O

Contents

Abstract HP Fortran Programmer GuidePage Contents Controlling data storage Using the on statementDebugging Performance and optimization Writing HP-UX applications 107 Using Fortran directives 123Calling C routines from HP Fortran 110 Migrating to HP Fortran 131 Porting to HP Fortran 141 Fortran 2003 Features 151Documentation Feedback 153 Glossary 154 Index 159 HP secure development lifecycle HP Fortran compiler environment An overview of HP FortranAn overview of HP Fortran Options for controlling the f90 driver Driver+dryrun +preinclude= file Options for controlling the C preprocessor Preprocessor Options for controlling the front end Front-end +moddir=directory Options for controlling optimization Back-end +Onooptimization Options for controlling code generationOptimization +DAmodel Options for controlling the Linker Linker Ldirectory +FPflagsOoutfile HP-UX operating system ToolsWl ,options F90 command syntax Compiling with the f90 commandCompiling and linking $ f90 hello.f90 F90 command syntax Command-line optionsCommand-line options Example 2 hello.f90 Commonly-used options Command-line options by categoryCommonly-used options +save Options listed by category Option descriptions Do I+1, N Example 3 Example+allowunaligned 14164 Data type sizes and +autodbl4+autodbl +autodbl4 Boption +charlit77 +cpp=default+check=bounds +nocfc +DAmodel Name=def+DDdatamodel Datamodelare Itanium BlendedItanium2 Native Values for the +FP option Gformat77 Signals recognized by the +fpexception option+hugecommon Example 4 % f90 +hugecommon=results pcvals.f90 +indirectcommonlist=file /usr/include directory +noimplicitnone+initheapcomplex=rvalival +initheapinteger=ival Ipo +io77+nocheckuf +nolibs Requires concurrent use of the +Oprofile=use option Levels of optimizationWith different values of optlevel +noobjdebug +pa1 +nodemandload the default +demandload option. The default is +nodemandload+r8 +realconstant=single Tp,/usr/ccs/lbin/cpp Tx,pathF90com End.o Wx,arg1,arg2,...,argN Bdefault=symbol,symbol Symbol binding optionsBextern =symbol ,symbol Bhidden =symbol ,symbol Reviewing general optimization options Using optimization optionsF90 +O3 +Osize myprog.f90 +Onoall +Oconservative+Onoautopar +Oautopar and omit +Oparallel F90 +O3 +Onomoveflops +Ofltacc myprog.f90 Fine-tuning optimization options Default is +Odataprefetch Default is +Onocxlimitedrange+Ocachepadcommon option +Onocxlimitedrange +Onofastaccess +Onofenvaccess+Onoentrysched +Onofailsafe Optimizations performed by +Onofltacc +Onoinline +Oinlinebudget=n +Oinlinebudget enables+Onoinlinefilename +Onoinline=function1,function2 Millicode versions of intrinsic functions Values for the +Oinlinebudget option +Onoloopunroll=factor +inlinelevel num+Oloopunroll=4 +Onoloopunrolljam +Oparallelintrinsics Default is+Onoparmsoverlap+Onoparmsoverlap +Onopipeline +Onorecovery Default is +OnopromoteindirectcallsDefault is +Oshortdata=8 For +Oprofile=collectarc,stride Filenames recognized by f90 Filenames Linking with f90 vs. ld Linking HP Fortran programs Libraries linked by default on Itanium Libraries linked by default on PA-RISCLinking to libraries $ f90 -c hello.f90 # compile Linking HP Fortran 90 routines Linking to nondefault libraries Linking to shared libraries Additional HP Fortran librariesOpt/fortran90/lib/pa2064/ -lF90 -lisamstub Compiling programs with modules Special-purpose compilationsLibrary search rules $ f90 -Wl,-a,archive prog.f90 -lm Special-purpose compilations Example ExamplesExample 6 Example 2-2 main.f90 Example 7 Example 2-3 code.f90 Example 8 Example 2-4 data.f90 Compiling with make$ f90 -o dostats data.f90 code.f90 main.f90 $ dostats Managing .mod files Compiling for different PA-RISC machinesExample 9 Example 2-5 makefile $ make Compiling with +pic Creating shared libraries Linking with -b Using the C preprocessor Processing cpp directives Using the C preprocessorExample 13 Example 2-9 cppdirect.f90 $ f90 +cpp=yes -D Debug cppdirect.f90 Creating shared executables Creating demand-loadable executablesSaving the cpp output file Using environment variables Compiling in 64-bit mode$ f90 +noshared prog.f90 HP Fortran environment variables STF90COM64 environment variable F90ROOT environment variableHPF90OPTS environment variable $ f90 +list hello.f90 Floating installation Floating installationLpath environment variable Mpnumberofthreads environment variable Alternate-path/opt/fortran90.3.6.1 Setting up floating installation Disabling implicit typing Controlling data storageAutomatic and static variables Disabling implicit typing Controlling data storage Contains Increasing the precision of constants Increasing default data sizes Increasing default data sizes Increasing default data sizes Usr/lib/libpthread.sl Sharing data among programsWhich creates multiple threads Sharing data among programs $ gotosleep $ wakeup Modules vs. common blocksIm up Modules vs. common blocks Debugging Using the HP WDB debuggerStripping debugging information Signal Signals recognized by +fpexceptionHandling runtime exceptions Floating-point exceptions Floating-point exceptions Bus error exception= 1.0/0.0 Segmentation violation exception Illegal instruction exception Bad argument exception Using debugging lines Exceptions handled by the on statement Using the on statementOn REAL8 DIV 0 Call divzerotrap Exceptions handled by the on statement On Double Precision DIV 0 Call divzerotrap Actions specified by onExceptions handled by the on statement Terminating program execution Ignoring errorsExample 14 Example5-1 abort.f90 Example 15 Example5-2 ignore.f90 Trapping floating-point exceptions Calling a trap procedureTrapping integer overflow exceptions On Double Precision Overflow Call trap Allowing core dumps Trapping +Ctrl-C trap interruptsExample 17 Example5-4 callitrap.f90 On Real Overflow Ignore Example 18 Example 5-5 allowcore.f90 Using profilers Using profilersPerformance and optimization HP Caliper Opt/ansic/bin/cc -Aa +O3 -o program +Oprofile=collect Comparing Program PerformanceProgram.c Programprogramarguments Gprof Using Options to Control Data CollectionSpecifying PBO file names and locations $ gprof prog gprof.out Using +O to set optimization levels Using options to control optimizationProf $ f90 +O4 file.f90 +O2, -O Using the optimization options+O3 +O4 $ f90 +02 +Oaggressive +Osize prog.f90 Fine-tuning optimization options$ f90 +O4 +Oaggressive +Ofltacc prog.f90 Packaged optimization options +Ofastaccess at level Is +Onofastaccess at+O2 +Ofltacc=relaxed Fast +Ofltacc=relaxed . This+Onoinitcheck +Onolibcalls +Oinlinelevel num+Olibcalls +Onoloopunroll=n +Opipeline +Onoparminit +Orecovery +Onoreturn +Oregreassoc+Oshortdata=8 +Ovectorize option on +Onowholeprogrammode Conservative vs. aggressive optimization+Owholeprogrammode Parallelizing HP Fortran programs Conservative, aggressive, and default optimizationsCompiling for parallel execution F90 +O3 +Oparallel -c x.f90 y.f90 F90 +O3 -c z.f90 Profiling parallelized programs Performance and parallelizationConditions inhibiting loop parallelization Calling routines with side effects parallellization Data dependences Indeterminate iteration counts Vectorization Using the +Ovectorize optionF90 +O3 +Ovectorize prog.f90 Vector routines called by +Ovectorize Saxpy Controlling vectorization locallySdot Vecdmultadd Example 19 Example 6-1 axpy.f90 Calling Blas library routinesREAL, External sdot Industry-wide standard Vectorization Controlling code generation for performance Writing HP-UX applications Accessing command-line arguments$ fprog arg1 another arg Example 20 Example 7-1 getargs.f90 Stream I/O using Fstream Using HP-UX file I/OPerforming I/O using HP-UX system calls Calling HP-UX system and library routines Obtaining an HP-UX file descriptor Using HP-UX file I/O Data types Calling C routines from HP FortranData type correspondence for HP Fortran and C Logicals Unsigned integersSize differences between HP Fortran and C data types Size differences after compiling with +autodbl Complex sqrcomplexCOMPLEX cmxval Complex numbersExample 21 Example 8-1 passcomplex.f90 Derived types Argument-passing conventionsPointers Example 22 Example 8-2 sqrcomplex.c Case sensitivity Integer ptr INTEGER, DIMENSION100 iarrayVoid fooint *ptr, int iarray100, int Call foo%REFptr, %REFiarray, %VALi $HP$ Alias bubblesort = BubbleSort%REF,%VAL Example 23 Example 8-3 sortem.cExample 24 Example 8-4 testsort.f90 Case sensitivity REAL, DIMENSION2,3,4 Memory layout of a two-dimensional array in Fortran and CArrays Int Example 26 Example 8-6 getarray.c Example 25 Example 8-5 passarray.f90 Null-terminated string StringsFortran hidden length argument Passing a string Strings Following are example C and Fortran programs Example 27 Example 8-7 passchars.f90 File handlingExample 28 Example 8-8 getstring.c File handling Example 29 Example 8-9 fnumtest.f90 Int somedata Sharing dataExtern int somedata Extern int globals100 Using HP Fortran directives Using Fortran directivesDirective syntax HP Fortran directives Description and restrictions Syntax$HP$ Alias name = external-name arg-pass-mode-list Name Case sensitivity Local and global usageArgument-passing conventions For more information StringsExample 31 Example 9-1 prstr.c Example 32 Example 9-2 passstr.f90 Specified on the command line Disables the inclusion of source lines in the listing fileExample 33 Example Listing file Controlling vectorization Compatibility directivesCompatibility directives recognized by HP Fortran Vendor Directive Cray Controlling dependence checks Controlling parallelizationControlling checks for side effects Compatibility directives Using Fortran directives Migrating to HP Fortran Command-line options not supportedIncompatibilities with HP Fortran Compiler limits Floating-point constants Format field widthsIntrinsic functions Double Precision x = Data types and constants Procedure calls and definitions Directives Input/outputFoo**REALbar, 8 ! foo**bar KEY= Source code issues Migration issuesMigration issues Miscellaneous HP Fortran 77 directives supported by f90 options Directives Intrinsic functions Command-line option issuesConflicting intrinsics and libU77 routine names F77 options supported by f90 Data file issues Object code issues HP-supplied migration tools Approaches to migration $ fid +800 file.f $ fid +es program.f Compatibility extensions Porting to HP FortranCompatibility statements END structure definition Compatibility directives Compiler directivesPointer Cray-style +Oparallel or Nonstandard intrinsic procedures in HP Fortran Intrinsic proceduresDirective prefixes recognized by HP Fortran +Oparallel or +Ovectorize Uninitialized variables Using porting options Large word size Using porting optionsOne-trip do loops $ f90 testloop.f90 Example 34 Example 11-1 clash.f90 Name conflictsExternal int1 Source formats Names with appended underscores Escape sequences Porting from Tru64 to HP Fortran+cfc New options EnhancementsNof66alternate for +noonetrip Porting from Tru64 to HP Fortran +nopadsrc Altparam Check noboundsoptions for example, -nocheckbounds Interoperability with C Fortran 2003 FeaturesInput/output enhancements Miscellaneous enhancements Fortran 2003 Features Object orientation featuresData enhancements 153 Documentation Feedback Glossary Glossary 155 So on. See also row-major order Also filename extension 157 Memory fault See ttv Index Symbols159