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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 bounds.

-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

-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,

-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 dble.

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

-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 ints.

-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

-R Do not promote REAL functions and operations to DOUBLE PRECISION. Option `-!R'
confirms the default, which imitates f77.

-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.

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