Short Table of Contents
- 1 Introduction
- 2 GNU Fortran Command Options
- 3 Runtime: Influencing runtime behavior with environment variables
- 4 Compiler Characteristics
- 5 Extensions
- 6 Mixed-Language Programming
- 7 Coarray Programming
- 8 Intrinsic Procedures
- 9 Intrinsic Modules
- Contributing
- GNU General Public License
- GNU Free Documentation License
- Funding Free Software
- Option Index
- Keyword Index
Table of Contents
- 1 Introduction
- 2 GNU Fortran Command Options
- 2.1 Option summary
- 2.2 Options controlling Fortran dialect
- 2.3 Enable and customize preprocessing
- 2.4 Options to request or suppress errors and warnings
- 2.5 Options for debugging your program or GNU Fortran
- 2.6 Options for directory search
- 2.7 Influencing the linking step
- 2.8 Influencing runtime behavior
- 2.9 Options for code generation conventions
- 2.10 Options for interoperability with other languages
- 2.11 Environment variables affecting
gfortran
- 3 Runtime: Influencing runtime behavior with environment variables
- 3.1
TMPDIR—Directory for scratch files - 3.2
GFORTRAN_STDIN_UNIT—Unit number for standard input - 3.3
GFORTRAN_STDOUT_UNIT—Unit number for standard output - 3.4
GFORTRAN_STDERR_UNIT—Unit number for standard error - 3.5
GFORTRAN_UNBUFFERED_ALL—Do not buffer I/O on all units - 3.6
GFORTRAN_UNBUFFERED_PRECONNECTED—Do not buffer I/O on preconnected units - 3.7
GFORTRAN_SHOW_LOCUS—Show location for runtime errors - 3.8
GFORTRAN_OPTIONAL_PLUS—Print leading + where permitted - 3.9
GFORTRAN_LIST_SEPARATOR—Separator for list output - 3.10
GFORTRAN_CONVERT_UNIT—Set conversion for unformatted I/O - 3.11
GFORTRAN_ERROR_BACKTRACE—Show backtrace on run-time errors - 3.12
GFORTRAN_FORMATTED_BUFFER_SIZE—Set buffer size for formatted I/O - 3.13
GFORTRAN_UNFORMATTED_BUFFER_SIZE—Set buffer size for unformatted I/O
- 3.1
- 4 Compiler Characteristics
- 4.1 KIND Type Parameters
- 4.2 Internal representation of LOGICAL variables
- 4.3 Evaluation of logical expressions
- 4.4 MAX and MIN intrinsics with REAL NaN arguments
- 4.5 Thread-safety of the runtime library
- 4.6 Data consistency and durability
- 4.7 Files opened without an explicit ACTION= specifier
- 4.8 File operations on symbolic links
- 4.9 File format of unformatted sequential files
- 4.10 Asynchronous I/O
- 4.11 Behavior on integer overflow
- 5 Extensions
- 5.1 Extensions implemented in GNU Fortran
- 5.1.1 Old-style kind specifications
- 5.1.2 Old-style variable initialization
- 5.1.3 Extensions to namelist
- 5.1.4
Xformat descriptor without count field - 5.1.5 Commas in
FORMATspecifications - 5.1.6 Missing period in
FORMATspecifications - 5.1.7 Default widths for
F,GandIformat descriptors - 5.1.8 I/O item lists
- 5.1.9
Qexponent-letter - 5.1.10 BOZ literal constants
- 5.1.11 Real array indices
- 5.1.12 Unary operators
- 5.1.13 Implicitly convert
LOGICALandINTEGERvalues - 5.1.14 Hollerith constants support
- 5.1.15 Character conversion
- 5.1.16 Cray pointers
- 5.1.17
CONVERTspecifier - 5.1.18 OpenMP
- 5.1.19 OpenACC
- 5.1.20 Argument list functions
%VAL,%REFand%LOC - 5.1.21 Read/Write after EOF marker
- 5.1.22
STRUCTUREandRECORD - 5.1.23
UNIONandMAP - 5.1.24 Type variants for integer intrinsics
- 5.1.25
AUTOMATICandSTATICattributes - 5.1.26 Extended math intrinsics
- 5.1.27 Form feed as whitespace
- 5.1.28 TYPE as an alias for PRINT
- 5.1.29 %LOC as an rvalue
- 5.1.30 .XOR. operator
- 5.1.31 Bitwise logical operators
- 5.1.32 Extended I/O specifiers
- 5.1.33 Legacy PARAMETER statements
- 5.1.34 Default exponents
- 5.2 Extensions not implemented in GNU Fortran
- 5.1 Extensions implemented in GNU Fortran
- 6 Mixed-Language Programming
- 6.1 Interoperability with C
- 6.2 GNU Fortran Compiler Directives
- 6.3 Non-Fortran Main Program
- 6.3.1
_gfortran_set_args— Save command-line arguments - 6.3.2
_gfortran_set_options— Set library option flags - 6.3.3
_gfortran_set_convert— Set endian conversion - 6.3.4
_gfortran_set_record_marker— Set length of record markers - 6.3.5
_gfortran_set_fpe— Enable floating point exception traps - 6.3.6
_gfortran_set_max_subrecord_length— Set subrecord length
- 6.3.1
- 6.4 Naming and argument-passing conventions
- 7 Coarray Programming
- 7.1 Type and enum ABI Documentation
- 7.2 Function ABI Documentation
- 7.2.1
_gfortran_caf_init— Initialiation function - 7.2.2
_gfortran_caf_finish— Finalization function - 7.2.3
_gfortran_caf_this_image— Querying the image number - 7.2.4
_gfortran_caf_num_images— Querying the maximal number of images - 7.2.5
_gfortran_caf_image_status— Query the status of an image - 7.2.6
_gfortran_caf_failed_images— Get an array of the indexes of the failed images - 7.2.7
_gfortran_caf_stopped_images— Get an array of the indexes of the stopped images - 7.2.8
_gfortran_caf_register— Registering coarrays - 7.2.9
_gfortran_caf_deregister— Deregistering coarrays - 7.2.10
_gfortran_caf_is_present— Query whether an allocatable or pointer component in a derived type coarray is allocated - 7.2.11
_gfortran_caf_send— Sending data from a local image to a remote image - 7.2.12
_gfortran_caf_get— Getting data from a remote image - 7.2.13
_gfortran_caf_sendget— Sending data between remote images - 7.2.14
_gfortran_caf_send_by_ref— Sending data from a local image to a remote image with enhanced referencing options - 7.2.15
_gfortran_caf_get_by_ref— Getting data from a remote image using enhanced references - 7.2.16
_gfortran_caf_sendget_by_ref— Sending data between remote images using enhanced references on both sides - 7.2.17
_gfortran_caf_lock— Locking a lock variable - 7.2.18
_gfortran_caf_lock— Unlocking a lock variable - 7.2.19
_gfortran_caf_event_post— Post an event - 7.2.20
_gfortran_caf_event_wait— Wait that an event occurred - 7.2.21
_gfortran_caf_event_query— Query event count - 7.2.22
_gfortran_caf_sync_all— All-image barrier - 7.2.23
_gfortran_caf_sync_images— Barrier for selected images - 7.2.24
_gfortran_caf_sync_memory— Wait for completion of segment-memory operations - 7.2.25
_gfortran_caf_error_stop— Error termination with exit code - 7.2.26
_gfortran_caf_error_stop_str— Error termination with string - 7.2.27
_gfortran_caf_fail_image— Mark the image failed and end its execution - 7.2.28
_gfortran_caf_atomic_define— Atomic variable assignment - 7.2.29
_gfortran_caf_atomic_ref— Atomic variable reference - 7.2.30
_gfortran_caf_atomic_cas— Atomic compare and swap - 7.2.31
_gfortran_caf_atomic_op— Atomic operation - 7.2.32
_gfortran_caf_co_broadcast— Sending data to all images - 7.2.33
_gfortran_caf_co_max— Collective maximum reduction - 7.2.34
_gfortran_caf_co_min— Collective minimum reduction - 7.2.35
_gfortran_caf_co_sum— Collective summing reduction - 7.2.36
_gfortran_caf_co_reduce— Generic collective reduction
- 7.2.1
- 8 Intrinsic Procedures
- 8.1 Introduction to intrinsic procedures
- 8.2
ABORT— Abort the program - 8.3
ABS— Absolute value - 8.4
ACCESS— Checks file access modes - 8.5
ACHAR— Character in ASCII collating sequence - 8.6
ACOS— Arccosine function - 8.7
ACOSD— Arccosine function, degrees - 8.8
ACOSH— Inverse hyperbolic cosine function - 8.9
ADJUSTL— Left adjust a string - 8.10
ADJUSTR— Right adjust a string - 8.11
AIMAG— Imaginary part of complex number - 8.12
AINT— Truncate to a whole number - 8.13
ALARM— Execute a routine after a given delay - 8.14
ALL— All values in MASK along DIM are true - 8.15
ALLOCATED— Status of an allocatable entity - 8.16
AND— Bitwise logical AND - 8.17
ANINT— Nearest whole number - 8.18
ANY— Any value in MASK along DIM is true - 8.19
ASIN— Arcsine function - 8.20
ASIND— Arcsine function, degrees - 8.21
ASINH— Inverse hyperbolic sine function - 8.22
ASSOCIATED— Status of a pointer or pointer/target pair - 8.23
ATAN— Arctangent function - 8.24
ATAND— Arctangent function, degrees - 8.25
ATAN2— Arctangent function - 8.26
ATAN2D— Arctangent function, degrees - 8.27
ATANH— Inverse hyperbolic tangent function - 8.28
ATOMIC_ADD— Atomic ADD operation - 8.29
ATOMIC_AND— Atomic bitwise AND operation - 8.30
ATOMIC_CAS— Atomic compare and swap - 8.31
ATOMIC_DEFINE— Setting a variable atomically - 8.32
ATOMIC_FETCH_ADD— Atomic ADD operation with prior fetch - 8.33
ATOMIC_FETCH_AND— Atomic bitwise AND operation with prior fetch - 8.34
ATOMIC_FETCH_OR— Atomic bitwise OR operation with prior fetch - 8.35
ATOMIC_FETCH_XOR— Atomic bitwise XOR operation with prior fetch - 8.36
ATOMIC_OR— Atomic bitwise OR operation - 8.37
ATOMIC_REF— Obtaining the value of a variable atomically - 8.38
ATOMIC_XOR— Atomic bitwise OR operation - 8.39
BACKTRACE— Show a backtrace - 8.40
BESSEL_J0— Bessel function of the first kind of order 0 - 8.41
BESSEL_J1— Bessel function of the first kind of order 1 - 8.42
BESSEL_JN— Bessel function of the first kind - 8.43
BESSEL_Y0— Bessel function of the second kind of order 0 - 8.44
BESSEL_Y1— Bessel function of the second kind of order 1 - 8.45
BESSEL_YN— Bessel function of the second kind - 8.46
BGE— Bitwise greater than or equal to - 8.47
BGT— Bitwise greater than - 8.48
BIT_SIZE— Bit size inquiry function - 8.49
BLE— Bitwise less than or equal to - 8.50
BLT— Bitwise less than - 8.51
BTEST— Bit test function - 8.52
C_ASSOCIATED— Status of a C pointer - 8.53
C_F_POINTER— Convert C into Fortran pointer - 8.54
C_F_PROCPOINTER— Convert C into Fortran procedure pointer - 8.55
C_FUNLOC— Obtain the C address of a procedure - 8.56
C_LOC— Obtain the C address of an object - 8.57
C_SIZEOF— Size in bytes of an expression - 8.58
CEILING— Integer ceiling function - 8.59
CHAR— Character conversion function - 8.60
CHDIR— Change working directory - 8.61
CHMOD— Change access permissions of files - 8.62
CMPLX— Complex conversion function - 8.63
CO_BROADCAST— Copy a value to all images the current set of images - 8.64
CO_MAX— Maximal value on the current set of images - 8.65
CO_MIN— Minimal value on the current set of images - 8.66
CO_REDUCE— Reduction of values on the current set of images - 8.67
CO_SUM— Sum of values on the current set of images - 8.68
COMMAND_ARGUMENT_COUNT— Get number of command line arguments - 8.69
COMPILER_OPTIONS— Options passed to the compiler - 8.70
COMPILER_VERSION— Compiler version string - 8.71
COMPLEX— Complex conversion function - 8.72
CONJG— Complex conjugate function - 8.73
COS— Cosine function - 8.74
COSD— Cosine function, degrees - 8.75
COSH— Hyperbolic cosine function - 8.76
COTAN— Cotangent function - 8.77
COTAND— Cotangent function, degrees - 8.78
COUNT— Count function - 8.79
CPU_TIME— CPU elapsed time in seconds - 8.80
CSHIFT— Circular shift elements of an array - 8.81
CTIME— Convert a time into a string - 8.82
DATE_AND_TIME— Date and time subroutine - 8.83
DBLE— Double conversion function - 8.84
DCMPLX— Double complex conversion function - 8.85
DIGITS— Significant binary digits function - 8.86
DIM— Positive difference - 8.87
DOT_PRODUCT— Dot product function - 8.88
DPROD— Double product function - 8.89
DREAL— Double real part function - 8.90
DSHIFTL— Combined left shift - 8.91
DSHIFTR— Combined right shift - 8.92
DTIME— Execution time subroutine (or function) - 8.93
EOSHIFT— End-off shift elements of an array - 8.94
EPSILON— Epsilon function - 8.95
ERF— Error function - 8.96
ERFC— Error function - 8.97
ERFC_SCALED— Error function - 8.98
ETIME— Execution time subroutine (or function) - 8.99
EVENT_QUERY— Query whether a coarray event has occurred - 8.100
EXECUTE_COMMAND_LINE— Execute a shell command - 8.101
EXIT— Exit the program with status. - 8.102
EXP— Exponential function - 8.103
EXPONENT— Exponent function - 8.104
EXTENDS_TYPE_OF— Query dynamic type for extension - 8.105
FDATE— Get the current time as a string - 8.106
FGET— Read a single character in stream mode from stdin - 8.107
FGETC— Read a single character in stream mode - 8.108
FINDLOC— Search an array for a value - 8.109
FLOOR— Integer floor function - 8.110
FLUSH— Flush I/O unit(s) - 8.111
FNUM— File number function - 8.112
FPUT— Write a single character in stream mode to stdout - 8.113
FPUTC— Write a single character in stream mode - 8.114
FRACTION— Fractional part of the model representation - 8.115
FREE— Frees memory - 8.116
FSEEK— Low level file positioning subroutine - 8.117
FSTAT— Get file status - 8.118
FTELL— Current stream position - 8.119
GAMMA— Gamma function - 8.120
GERROR— Get last system error message - 8.121
GETARG— Get command line arguments - 8.122
GET_COMMAND— Get the entire command line - 8.123
GET_COMMAND_ARGUMENT— Get command line arguments - 8.124
GETCWD— Get current working directory - 8.125
GETENV— Get an environmental variable - 8.126
GET_ENVIRONMENT_VARIABLE— Get an environmental variable - 8.127
GETGID— Group ID function - 8.128
GETLOG— Get login name - 8.129
GETPID— Process ID function - 8.130
GETUID— User ID function - 8.131
GMTIME— Convert time to GMT info - 8.132
HOSTNM— Get system host name - 8.133
HUGE— Largest number of a kind - 8.134
HYPOT— Euclidean distance function - 8.135
IACHAR— Code in ASCII collating sequence - 8.136
IALL— Bitwise AND of array elements - 8.137
IAND— Bitwise logical and - 8.138
IANY— Bitwise OR of array elements - 8.139
IARGC— Get the number of command line arguments - 8.140
IBCLR— Clear bit - 8.141
IBITS— Bit extraction - 8.142
IBSET— Set bit - 8.143
ICHAR— Character-to-integer conversion function - 8.144
IDATE— Get current local time subroutine (day/month/year) - 8.145
IEOR— Bitwise logical exclusive or - 8.146
IERRNO— Get the last system error number - 8.147
IMAGE_INDEX— Function that converts a cosubscript to an image index - 8.148
INDEX— Position of a substring within a string - 8.149
INT— Convert to integer type - 8.150
INT2— Convert to 16-bit integer type - 8.151
INT8— Convert to 64-bit integer type - 8.152
IOR— Bitwise logical or - 8.153
IPARITY— Bitwise XOR of array elements - 8.154
IRAND— Integer pseudo-random number - 8.155
IS_CONTIGUOUS— Test whether an array is contiguous - 8.156
IS_IOSTAT_END— Test for end-of-file value - 8.157
IS_IOSTAT_EOR— Test for end-of-record value - 8.158
ISATTY— Whether a unit is a terminal device - 8.159
ISHFT— Shift bits - 8.160
ISHFTC— Shift bits circularly - 8.161
ISNAN— Test for a NaN - 8.162
ITIME— Get current local time subroutine (hour/minutes/seconds) - 8.163
KILL— Send a signal to a process - 8.164
KIND— Kind of an entity - 8.165
LBOUND— Lower dimension bounds of an array - 8.166
LCOBOUND— Lower codimension bounds of an array - 8.167
LEADZ— Number of leading zero bits of an integer - 8.168
LEN— Length of a character entity - 8.169
LEN_TRIM— Length of a character entity without trailing blank characters - 8.170
LGE— Lexical greater than or equal - 8.171
LGT— Lexical greater than - 8.172
LINK— Create a hard link - 8.173
LLE— Lexical less than or equal - 8.174
LLT— Lexical less than - 8.175
LNBLNK— Index of the last non-blank character in a string - 8.176
LOC— Returns the address of a variable - 8.177
LOG— Natural logarithm function - 8.178
LOG10— Base 10 logarithm function - 8.179
LOG_GAMMA— Logarithm of the Gamma function - 8.180
LOGICAL— Convert to logical type - 8.181
LSHIFT— Left shift bits - 8.182
LSTAT— Get file status - 8.183
LTIME— Convert time to local time info - 8.184
MALLOC— Allocate dynamic memory - 8.185
MASKL— Left justified mask - 8.186
MASKR— Right justified mask - 8.187
MATMUL— matrix multiplication - 8.188
MAX— Maximum value of an argument list - 8.189
MAXEXPONENT— Maximum exponent of a real kind - 8.190
MAXLOC— Location of the maximum value within an array - 8.191
MAXVAL— Maximum value of an array - 8.192
MCLOCK— Time function - 8.193
MCLOCK8— Time function (64-bit) - 8.194
MERGE— Merge variables - 8.195
MERGE_BITS— Merge of bits under mask - 8.196
MIN— Minimum value of an argument list - 8.197
MINEXPONENT— Minimum exponent of a real kind - 8.198
MINLOC— Location of the minimum value within an array - 8.199
MINVAL— Minimum value of an array - 8.200
MOD— Remainder function - 8.201
MODULO— Modulo function - 8.202
MOVE_ALLOC— Move allocation from one object to another - 8.203
MVBITS— Move bits from one integer to another - 8.204
NEAREST— Nearest representable number - 8.205
NEW_LINE— New line character - 8.206
NINT— Nearest whole number - 8.207
NORM2— Euclidean vector norms - 8.208
NOT— Logical negation - 8.209
NULL— Function that returns an disassociated pointer - 8.210
NUM_IMAGES— Function that returns the number of images - 8.211
OR— Bitwise logical OR - 8.212
PACK— Pack an array into an array of rank one - 8.213
PARITY— Reduction with exclusive OR - 8.214
PERROR— Print system error message - 8.215
POPCNT— Number of bits set - 8.216
POPPAR— Parity of the number of bits set - 8.217
PRECISION— Decimal precision of a real kind - 8.218
PRESENT— Determine whether an optional dummy argument is specified - 8.219
PRODUCT— Product of array elements - 8.220
RADIX— Base of a model number - 8.221
RAN— Real pseudo-random number - 8.222
RAND— Real pseudo-random number - 8.223
RANDOM_INIT— Initialize a pseudo-random number generator - 8.224
RANDOM_NUMBER— Pseudo-random number - 8.225
RANDOM_SEED— Initialize a pseudo-random number sequence - 8.226
RANGE— Decimal exponent range - 8.227
RANK— Rank of a data object - 8.228
REAL— Convert to real type - 8.229
RENAME— Rename a file - 8.230
REPEAT— Repeated string concatenation - 8.231
RESHAPE— Function to reshape an array - 8.232
RRSPACING— Reciprocal of the relative spacing - 8.233
RSHIFT— Right shift bits - 8.234
SAME_TYPE_AS— Query dynamic types for equality - 8.235
SCALE— Scale a real value - 8.236
SCAN— Scan a string for the presence of a set of characters - 8.237
SECNDS— Time function - 8.238
SECOND— CPU time function - 8.239
SELECTED_CHAR_KIND— Choose character kind - 8.240
SELECTED_INT_KIND— Choose integer kind - 8.241
SELECTED_REAL_KIND— Choose real kind - 8.242
SET_EXPONENT— Set the exponent of the model - 8.243
SHAPE— Determine the shape of an array - 8.244
SHIFTA— Right shift with fill - 8.245
SHIFTL— Left shift - 8.246
SHIFTR— Right shift - 8.247
SIGN— Sign copying function - 8.248
SIGNAL— Signal handling subroutine (or function) - 8.249
SIN— Sine function - 8.250
SIND— Sine function, degrees - 8.251
SINH— Hyperbolic sine function - 8.252
SIZE— Determine the size of an array - 8.253
SIZEOF— Size in bytes of an expression - 8.254
SLEEP— Sleep for the specified number of seconds - 8.255
SPACING— Smallest distance between two numbers of a given type - 8.256
SPREAD— Add a dimension to an array - 8.257
SQRT— Square-root function - 8.258
SRAND— Reinitialize the random number generator - 8.259
STAT— Get file status - 8.260
STORAGE_SIZE— Storage size in bits - 8.261
SUM— Sum of array elements - 8.262
SYMLNK— Create a symbolic link - 8.263
SYSTEM— Execute a shell command - 8.264
SYSTEM_CLOCK— Time function - 8.265
TAN— Tangent function - 8.266
TAND— Tangent function, degrees - 8.267
TANH— Hyperbolic tangent function - 8.268
THIS_IMAGE— Function that returns the cosubscript index of this image - 8.269
TIME— Time function - 8.270
TIME8— Time function (64-bit) - 8.271
TINY— Smallest positive number of a real kind - 8.272
TRAILZ— Number of trailing zero bits of an integer - 8.273
TRANSFER— Transfer bit patterns - 8.274
TRANSPOSE— Transpose an array of rank two - 8.275
TRIM— Remove trailing blank characters of a string - 8.276
TTYNAM— Get the name of a terminal device - 8.277
UBOUND— Upper dimension bounds of an array - 8.278
UCOBOUND— Upper codimension bounds of an array - 8.279
UMASK— Set the file creation mask - 8.280
UNLINK— Remove a file from the file system - 8.281
UNPACK— Unpack an array of rank one into an array - 8.282
VERIFY— Scan a string for characters not a given set - 8.283
XOR— Bitwise logical exclusive OR
- 9 Intrinsic Modules
- Contributing
- GNU General Public License
- GNU Free Documentation License
- Funding Free Software
- Option Index
- Keyword Index
Introduction ¶
This manual documents the use of gfortran, the GNU Fortran compiler. You can find in this manual how to invoke gfortran, as well as its features and incompatibilities.
- Introduction
- GNU Fortran Command Options
- Runtime: Influencing runtime behavior with environment variables
- Compiler Characteristics
- Extensions
- Mixed-Language Programming
- Coarray Programming
- Intrinsic Procedures
- Intrinsic Modules
- Contributing
- GNU General Public License
- GNU Free Documentation License
- Funding Free Software
- Option Index
- Keyword Index
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-13.1.0/gfortran/index.html