F2C(1) manual page

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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, INTEGER4 as long int. Assume the default libF77 and libI77: allow only INTEGER4 (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 CW-I options (one directory per option). Options CW-I2 and CW-I4 have precedence, so, e.g., a directory named CW2 should be specified by CW-I./2 .
-onetrip: 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 is old-style C.
-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.
-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 CW#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 of ANSI (or C++) prototypes for definitions in each input or 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 f77.
-r: Cast values of REAL functions (including intrinsics) to REAL.
-r8: Promote REAL to DOUBLE PRECISION, COMPLEX to DOUBLE COMPLEX.
-s: Preserve multidimensional subscripts. Suppressed by option %`-C' .
-Tdir: Put temporary files in directory dir.
-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: Reject include statements.
-!i8: Disallow INTEGER*8.
-!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.

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.

FILES

input file
*.c: output file
%/usr/include/f2c.h: header file
%/usr/lib/libF77.a: intrinsic function library
%/usr/lib/libI77.a: Fortran I/O library
%/lib/libc.a: C library, see section 3

DIAGNOSTICS

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

BUGS

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.

Table of Contents

NAME

SYNOPSIS

DESCRIPTION

FILES

SEE ALSO

DIAGNOSTICS

BUGS