F2C(1)                      General Commands Manual                     F2C(1)

       f2c - Convert Fortran 77 to C or C++

       f2c [ option ...  ] file ...

       F2c converts Fortran 77 source code in files with names ending in `.f'
       or `.F' to C (or C++) source files in the current directory, with `.c'
       substituted for the final `.f' or `.F'.  If no Fortran files are named,
       f2c reads Fortran from standard input and writes C on standard output.
       File names that end with `.p' or `.P' are taken to be prototype files,
       as produced by option `-P', and are read first.

       The following options have the same meaning as in f77(1).

       -C     Compile code to check that subscripts are within declared array

       -I2    Render INTEGER and LOGICAL as short, INTEGER∗4 as long int.
              Assume the default libF77 and libI77:  allow only INTEGER∗4 (and
              no LOGICAL) variables in INQUIREs.  Option `-I4' confirms the
              default rendering of INTEGER as long int.

       -Idir  Look for a non-absolute include file first in the directory of
              the current input file, then in directories specified by -I
              options (one directory per option).  Options -I2 and -I4 have
              precedence, so, e.g., a directory named 2 should be specified by
              -I./2 .

              Compile DO loops that are performed at least once if reached.
              (Fortran 77 DO loops are not performed at all if the upper limit
              is smaller than the lower limit.)

       -U     Honor the case of variable and external names.  Fortran keywords
              must be in lower case.

       -u     Make the default type of a variable `undefined' rather than
              using the default Fortran rules.

       -w     Suppress all warning messages, or, if the option is `-w66', just
              Fortran 66 compatibility warnings.

       The following options are peculiar to f2c.

       -A     Produce ANSI C (default, starting 20020621).  For old-style C,
              use option -K.

       -a     Make local variables automatic rather than static unless they
              appear in a DATA, EQUIVALENCE, NAMELIST, or SAVE statement.

       -C++   Output C++ code.

       -c     Include original Fortran source as comments.

       -cd    Do not recognize cdabs, cdcos, cdexp, cdlog, cdsin, and cdsqrt
              as synonyms for the double complex intrinsics zabs, zcos, zexp,
              zlog, zsin, and zsqrt, respectively, nor dreal as a synonym for

       -ddir  Write `.c' files in directory dir instead of the current

       -E     Declare uninitialized COMMON to be Extern (overridably defined
              in f2c.h as extern).

       -ec    Place uninitialized COMMON blocks in separate files: COMMON
              /ABC/ appears in file abc_com.c.  Option `-e1c' bundles the
              separate files into the output file, with comments that give an
              unbundling sed(1) script.

       -ext   Complain about f77(1) extensions.

       -f     Assume free-format input: accept text after column 72 and do not
              pad fixed-format lines shorter than 72 characters with blanks.

       -72    Treat text appearing after column 72 as an error.

       -g     Include original Fortran line numbers in #line lines.

       -h     Emulate Fortran 66's treatment of Hollerith: try to align
              character strings on word (or, if the option is `-hd', on
              double-word) boundaries.

       -i2    Similar to -I2, but assume a modified libF77 and libI77
              (compiled with -Df2c_i2), so INTEGER and LOGICAL variables may
              be assigned by INQUIRE and array lengths are stored in short

       -i90   Do not recognize the Fortran 90 bit-manipulation intrinsics
              btest, iand, ibclr, ibits, ibset, ieor, ior, ishft, and ishftc.

       -kr    Use temporary values to enforce Fortran expression evaluation
              where K&R (first edition) parenthesization rules allow
              rearrangement.  If the option is `-krd', use double precision
              temporaries even for single-precision operands.

       -P     Write a file.P of ANSI (or C++) prototypes for definitions in
              each input file.f or file.F.  When reading Fortran from standard
              input, write prototypes at the beginning of standard output.
              Option -Ps implies -P and gives exit status 4 if rerunning f2c
              may change prototypes or declarations.

       -p     Supply preprocessor definitions to make common-block members
              look like local variables.

       -R     Do not promote REAL functions and operations to DOUBLE
              PRECISION.  Option `-!R' confirms the default, which imitates

       -r     Cast REAL arguments of intrinsic functions and values of REAL
              functions (including intrinsics) to REAL.


       -s     Preserve multidimensional subscripts.  Suppressed by option `-C'

       -Tdir  Put temporary files in directory dir.

              Dynamically initialize local variables, except those appearing
              in SAVE or DATA statements, with values that may help find
              references to uninitialized variables.  For example, with IEEE
              arithmetic, initialize local floating-point variables to
              signaling NaNs.

       -w8    Suppress warnings when COMMON or EQUIVALENCE forces odd-word
              alignment of doubles.

       -Wn    Assume n characters/word (default 4) when initializing numeric
              variables with character data.

       -z     Do not implicitly recognize DOUBLE COMPLEX.

       -!bs   Do not recognize backslash escapes (\", \', \0, \\, \b, \f, \n,
              \r, \t, \v) in character strings.

       -!c    Inhibit C output, but produce -P output.

       i-!I   Reject include statements.

       -!i8   Disallow INTEGER*8 , or, if the option is `-!i8const', permit
              INTEGER*8 but do not promote integer constants to INTEGER*8 when
              they involve more than 32 bits.

       -!it   Don't infer types of untyped EXTERNAL procedures from use as
              parameters to previously defined or prototyped procedures.

       -!P    Do not attempt to infer ANSI or C++ prototypes from usage.

       -v, --version
              Print the version number of f2c

       The resulting C invokes the support routines of f77; object code should
       be loaded by f77 or with ld(1) or cc(1) options -lF77 -lI77 -lm.
       Calling conventions are those of f77: see the reference below.

              input file

       *.c    output file

              header file

              static link intrinsic and I/O library

              static link intrinsic and I/O library for use with files
              translated using the -i2 f2c option

              shared object intrinsic and I/O library

              shared object intrinsic and I/O library for use with files
              translated using the -i2 f2c option

       SEE ALSO
              S. I. Feldman and P. J. Weinberger, `A Portable Fortran 77
              Compiler', UNIX Time Sharing System Programmer's Manual, Tenth
              Edition, Volume 2, AT&T Bell Laboratories, 1990.

       The diagnostics produced by f2c are intended to be self-explanatory.

       Floating-point constant expressions are simplified in the floating-
       point arithmetic of the machine running f2c, so they are typically
       accurate to at most 16 or 17 decimal places.
       Untypable EXTERNAL functions are declared int.
       There is no notation for INTEGER*8 constants.
       Some intrinsic functions do not yet work with INTEGER*8 .