The GNU Fortran Compiler
Short Table of Contents
- 1 Introduction
- 2 GNU Fortran Command Options
- 3 Runtime: Influencing runtime behavior with environment variables
- 4 Fortran 2003 and 2008 Status
- 5 Compiler Characteristics
- 6 Extensions
- 7 Mixed-Language Programming
- 8 Coarray Programming
- 9 Intrinsic Procedures
- 10 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 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_DEFAULT_RECL—Default record length for new files - 3.10
GFORTRAN_LIST_SEPARATOR—Separator for list output - 3.11
GFORTRAN_CONVERT_UNIT—Set endianness for unformatted I/O - 3.12
GFORTRAN_ERROR_BACKTRACE—Show backtrace on run-time errors
- 3.1
- 4 Fortran 2003 and 2008 Status
- 5 Compiler Characteristics
-
6 Extensions
-
6.1 Extensions implemented in GNU Fortran
- 6.1.1 Old-style kind specifications
- 6.1.2 Old-style variable initialization
- 6.1.3 Extensions to namelist
- 6.1.4
Xformat descriptor without count field - 6.1.5 Commas in
FORMATspecifications - 6.1.6 Missing period in
FORMATspecifications - 6.1.7 I/O item lists
- 6.1.8
Qexponent-letter - 6.1.9 BOZ literal constants
- 6.1.10 Real array indices
- 6.1.11 Unary operators
- 6.1.12 Implicitly convert
LOGICALandINTEGERvalues - 6.1.13 Hollerith constants support
- 6.1.14 Cray pointers
- 6.1.15
CONVERTspecifier - 6.1.16 OpenMP
- 6.1.17 OpenACC
- 6.1.18 Argument list functions
%VAL,%REFand%LOC - 6.1.19 Read/Write after EOF marker
- 6.1.20
STRUCTUREandRECORD - 6.1.21
UNIONandMAP
- 6.2 Extensions not implemented in GNU Fortran
-
6.1 Extensions implemented in GNU Fortran
-
7 Mixed-Language Programming
- 7.1 Interoperability with C
- 7.2 GNU Fortran Compiler Directives
-
7.3 Non-Fortran Main Program
- 7.3.1
_gfortran_set_args— Save command-line arguments - 7.3.2
_gfortran_set_options— Set library option flags - 7.3.3
_gfortran_set_convert— Set endian conversion - 7.3.4
_gfortran_set_record_marker— Set length of record markers - 7.3.5
_gfortran_set_fpe— Enable floating point exception traps - 7.3.6
_gfortran_set_max_subrecord_length— Set subrecord length
- 7.3.1
- 7.4 Naming and argument-passing conventions
-
8 Coarray Programming
- 8.1 Type and enum ABI Documentation
-
8.2 Function ABI Documentation
- 8.2.1
_gfortran_caf_init— Initialiation function - 8.2.2
_gfortran_caf_finish— Finalization function - 8.2.3
_gfortran_caf_this_image— Querying the image number - 8.2.4
_gfortran_caf_num_images— Querying the maximal number of images - 8.2.5
_gfortran_caf_register— Registering coarrays - 8.2.6
_gfortran_caf_deregister— Deregistering coarrays - 8.2.7
_gfortran_caf_send— Sending data from a local image to a remote image - 8.2.8
_gfortran_caf_get— Getting data from a remote image - 8.2.9
_gfortran_caf_sendget— Sending data between remote images - 8.2.10
_gfortran_caf_lock— Locking a lock variable - 8.2.11
_gfortran_caf_lock— Unlocking a lock variable - 8.2.12
_gfortran_caf_event_post— Post an event - 8.2.13
_gfortran_caf_event_wait— Wait that an event occurred - 8.2.14
_gfortran_caf_event_query— Query event count - 8.2.15
_gfortran_caf_sync_all— All-image barrier - 8.2.16
_gfortran_caf_sync_images— Barrier for selected images - 8.2.17
_gfortran_caf_sync_memory— Wait for completion of segment-memory operations - 8.2.18
_gfortran_caf_error_stop— Error termination with exit code - 8.2.19
_gfortran_caf_error_stop_str— Error termination with string - 8.2.20
_gfortran_caf_atomic_define— Atomic variable assignment - 8.2.21
_gfortran_caf_atomic_ref— Atomic variable reference - 8.2.22
_gfortran_caf_atomic_cas— Atomic compare and swap - 8.2.23
_gfortran_caf_atomic_op— Atomic operation - 8.2.24
_gfortran_caf_co_broadcast— Sending data to all images - 8.2.25
_gfortran_caf_co_max— Collective maximum reduction - 8.2.26
_gfortran_caf_co_min— Collective minimum reduction - 8.2.27
_gfortran_caf_co_sum— Collective summing reduction - 8.2.28
_gfortran_caf_co_reduce— Generic collective reduction
- 8.2.1
-
9 Intrinsic Procedures
- 9.1 Introduction to intrinsic procedures
- 9.2
ABORT— Abort the program - 9.3
ABS— Absolute value - 9.4
ACCESS— Checks file access modes - 9.5
ACHAR— Character in ASCII collating sequence - 9.6
ACOS— Arccosine function - 9.7
ACOSH— Inverse hyperbolic cosine function - 9.8
ADJUSTL— Left adjust a string - 9.9
ADJUSTR— Right adjust a string - 9.10
AIMAG— Imaginary part of complex number - 9.11
AINT— Truncate to a whole number - 9.12
ALARM— Execute a routine after a given delay - 9.13
ALL— All values in MASK along DIM are true - 9.14
ALLOCATED— Status of an allocatable entity - 9.15
AND— Bitwise logical AND - 9.16
ANINT— Nearest whole number - 9.17
ANY— Any value in MASK along DIM is true - 9.18
ASIN— Arcsine function - 9.19
ASINH— Inverse hyperbolic sine function - 9.20
ASSOCIATED— Status of a pointer or pointer/target pair - 9.21
ATAN— Arctangent function - 9.22
ATAN2— Arctangent function - 9.23
ATANH— Inverse hyperbolic tangent function - 9.24
ATOMIC_ADD— Atomic ADD operation - 9.25
ATOMIC_AND— Atomic bitwise AND operation - 9.26
ATOMIC_CAS— Atomic compare and swap - 9.27
ATOMIC_DEFINE— Setting a variable atomically - 9.28
ATOMIC_FETCH_ADD— Atomic ADD operation with prior fetch - 9.29
ATOMIC_FETCH_AND— Atomic bitwise AND operation with prior fetch - 9.30
ATOMIC_FETCH_OR— Atomic bitwise OR operation with prior fetch - 9.31
ATOMIC_FETCH_XOR— Atomic bitwise XOR operation with prior fetch - 9.32
ATOMIC_OR— Atomic bitwise OR operation - 9.33
ATOMIC_REF— Obtaining the value of a variable atomically - 9.34
ATOMIC_XOR— Atomic bitwise OR operation - 9.35
BACKTRACE— Show a backtrace - 9.36
BESSEL_J0— Bessel function of the first kind of order 0 - 9.37
BESSEL_J1— Bessel function of the first kind of order 1 - 9.38
BESSEL_JN— Bessel function of the first kind - 9.39
BESSEL_Y0— Bessel function of the second kind of order 0 - 9.40
BESSEL_Y1— Bessel function of the second kind of order 1 - 9.41
BESSEL_YN— Bessel function of the second kind - 9.42
BGE— Bitwise greater than or equal to - 9.43
BGT— Bitwise greater than - 9.44
BIT_SIZE— Bit size inquiry function - 9.45
BLE— Bitwise less than or equal to - 9.46
BLT— Bitwise less than - 9.47
BTEST— Bit test function - 9.48
C_ASSOCIATED— Status of a C pointer - 9.49
C_F_POINTER— Convert C into Fortran pointer - 9.50
C_F_PROCPOINTER— Convert C into Fortran procedure pointer - 9.51
C_FUNLOC— Obtain the C address of a procedure - 9.52
C_LOC— Obtain the C address of an object - 9.53
C_SIZEOF— Size in bytes of an expression - 9.54
CEILING— Integer ceiling function - 9.55
CHAR— Character conversion function - 9.56
CHDIR— Change working directory - 9.57
CHMOD— Change access permissions of files - 9.58
CMPLX— Complex conversion function - 9.59
CO_BROADCAST— Copy a value to all images the current set of images - 9.60
CO_MAX— Maximal value on the current set of images - 9.61
CO_MIN— Minimal value on the current set of images - 9.62
CO_REDUCE— Reduction of values on the current set of images - 9.63
CO_SUM— Sum of values on the current set of images - 9.64
COMMAND_ARGUMENT_COUNT— Get number of command line arguments - 9.65
COMPILER_OPTIONS— Options passed to the compiler - 9.66
COMPILER_VERSION— Compiler version string - 9.67
COMPLEX— Complex conversion function - 9.68
CONJG— Complex conjugate function - 9.69
COS— Cosine function - 9.70
COSH— Hyperbolic cosine function - 9.71
COUNT— Count function - 9.72
CPU_TIME— CPU elapsed time in seconds - 9.73
CSHIFT— Circular shift elements of an array - 9.74
CTIME— Convert a time into a string - 9.75
DATE_AND_TIME— Date and time subroutine - 9.76
DBLE— Double conversion function - 9.77
DCMPLX— Double complex conversion function - 9.78
DIGITS— Significant binary digits function - 9.79
DIM— Positive difference - 9.80
DOT_PRODUCT— Dot product function - 9.81
DPROD— Double product function - 9.82
DREAL— Double real part function - 9.83
DSHIFTL— Combined left shift - 9.84
DSHIFTR— Combined right shift - 9.85
DTIME— Execution time subroutine (or function) - 9.86
EOSHIFT— End-off shift elements of an array - 9.87
EPSILON— Epsilon function - 9.88
ERF— Error function - 9.89
ERFC— Error function - 9.90
ERFC_SCALED— Error function - 9.91
ETIME— Execution time subroutine (or function) - 9.92
EVENT_QUERY— Query whether a coarray event has occurred - 9.93
EXECUTE_COMMAND_LINE— Execute a shell command - 9.94
EXIT— Exit the program with status. - 9.95
EXP— Exponential function - 9.96
EXPONENT— Exponent function - 9.97
EXTENDS_TYPE_OF— Query dynamic type for extension - 9.98
FDATE— Get the current time as a string - 9.99
FGET— Read a single character in stream mode from stdin - 9.100
FGETC— Read a single character in stream mode - 9.101
FLOOR— Integer floor function - 9.102
FLUSH— Flush I/O unit(s) - 9.103
FNUM— File number function - 9.104
FPUT— Write a single character in stream mode to stdout - 9.105
FPUTC— Write a single character in stream mode - 9.106
FRACTION— Fractional part of the model representation - 9.107
FREE— Frees memory - 9.108
FSEEK— Low level file positioning subroutine - 9.109
FSTAT— Get file status - 9.110
FTELL— Current stream position - 9.111
GAMMA— Gamma function - 9.112
GERROR— Get last system error message - 9.113
GETARG— Get command line arguments - 9.114
GET_COMMAND— Get the entire command line - 9.115
GET_COMMAND_ARGUMENT— Get command line arguments - 9.116
GETCWD— Get current working directory - 9.117
GETENV— Get an environmental variable - 9.118
GET_ENVIRONMENT_VARIABLE— Get an environmental variable - 9.119
GETGID— Group ID function - 9.120
GETLOG— Get login name - 9.121
GETPID— Process ID function - 9.122
GETUID— User ID function - 9.123
GMTIME— Convert time to GMT info - 9.124
HOSTNM— Get system host name - 9.125
HUGE— Largest number of a kind - 9.126
HYPOT— Euclidean distance function - 9.127
IACHAR— Code in ASCII collating sequence - 9.128
IALL— Bitwise AND of array elements - 9.129
IAND— Bitwise logical and - 9.130
IANY— Bitwise OR of array elements - 9.131
IARGC— Get the number of command line arguments - 9.132
IBCLR— Clear bit - 9.133
IBITS— Bit extraction - 9.134
IBSET— Set bit - 9.135
ICHAR— Character-to-integer conversion function - 9.136
IDATE— Get current local time subroutine (day/month/year) - 9.137
IEOR— Bitwise logical exclusive or - 9.138
IERRNO— Get the last system error number - 9.139
IMAGE_INDEX— Function that converts a cosubscript to an image index - 9.140
INDEX— Position of a substring within a string - 9.141
INT— Convert to integer type - 9.142
INT2— Convert to 16-bit integer type - 9.143
INT8— Convert to 64-bit integer type - 9.144
IOR— Bitwise logical or - 9.145
IPARITY— Bitwise XOR of array elements - 9.146
IRAND— Integer pseudo-random number - 9.147
IS_IOSTAT_END— Test for end-of-file value - 9.148
IS_IOSTAT_EOR— Test for end-of-record value - 9.149
ISATTY— Whether a unit is a terminal device. - 9.150
ISHFT— Shift bits - 9.151
ISHFTC— Shift bits circularly - 9.152
ISNAN— Test for a NaN - 9.153
ITIME— Get current local time subroutine (hour/minutes/seconds) - 9.154
KILL— Send a signal to a process - 9.155
KIND— Kind of an entity - 9.156
LBOUND— Lower dimension bounds of an array - 9.157
LCOBOUND— Lower codimension bounds of an array - 9.158
LEADZ— Number of leading zero bits of an integer - 9.159
LEN— Length of a character entity - 9.160
LEN_TRIM— Length of a character entity without trailing blank characters - 9.161
LGE— Lexical greater than or equal - 9.162
LGT— Lexical greater than - 9.163
LINK— Create a hard link - 9.164
LLE— Lexical less than or equal - 9.165
LLT— Lexical less than - 9.166
LNBLNK— Index of the last non-blank character in a string - 9.167
LOC— Returns the address of a variable - 9.168
LOG— Natural logarithm function - 9.169
LOG10— Base 10 logarithm function - 9.170
LOG_GAMMA— Logarithm of the Gamma function - 9.171
LOGICAL— Convert to logical type - 9.172
LONG— Convert to integer type - 9.173
LSHIFT— Left shift bits - 9.174
LSTAT— Get file status - 9.175
LTIME— Convert time to local time info - 9.176
MALLOC— Allocate dynamic memory - 9.177
MASKL— Left justified mask - 9.178
MASKR— Right justified mask - 9.179
MATMUL— matrix multiplication - 9.180
MAX— Maximum value of an argument list - 9.181
MAXEXPONENT— Maximum exponent of a real kind - 9.182
MAXLOC— Location of the maximum value within an array - 9.183
MAXVAL— Maximum value of an array - 9.184
MCLOCK— Time function - 9.185
MCLOCK8— Time function (64-bit) - 9.186
MERGE— Merge variables - 9.187
MERGE_BITS— Merge of bits under mask - 9.188
MIN— Minimum value of an argument list - 9.189
MINEXPONENT— Minimum exponent of a real kind - 9.190
MINLOC— Location of the minimum value within an array - 9.191
MINVAL— Minimum value of an array - 9.192
MOD— Remainder function - 9.193
MODULO— Modulo function - 9.194
MOVE_ALLOC— Move allocation from one object to another - 9.195
MVBITS— Move bits from one integer to another - 9.196
NEAREST— Nearest representable number - 9.197
NEW_LINE— New line character - 9.198
NINT— Nearest whole number - 9.199
NORM2— Euclidean vector norms - 9.200
NOT— Logical negation - 9.201
NULL— Function that returns an disassociated pointer - 9.202
NUM_IMAGES— Function that returns the number of images - 9.203
OR— Bitwise logical OR - 9.204
PACK— Pack an array into an array of rank one - 9.205
PARITY— Reduction with exclusive OR - 9.206
PERROR— Print system error message - 9.207
POPCNT— Number of bits set - 9.208
POPPAR— Parity of the number of bits set - 9.209
PRECISION— Decimal precision of a real kind - 9.210
PRESENT— Determine whether an optional dummy argument is specified - 9.211
PRODUCT— Product of array elements - 9.212
RADIX— Base of a model number - 9.213
RAN— Real pseudo-random number - 9.214
RAND— Real pseudo-random number - 9.215
RANDOM_NUMBER— Pseudo-random number - 9.216
RANDOM_SEED— Initialize a pseudo-random number sequence - 9.217
RANGE— Decimal exponent range - 9.218
RANK— Rank of a data object - 9.219
REAL— Convert to real type - 9.220
RENAME— Rename a file - 9.221
REPEAT— Repeated string concatenation - 9.222
RESHAPE— Function to reshape an array - 9.223
RRSPACING— Reciprocal of the relative spacing - 9.224
RSHIFT— Right shift bits - 9.225
SAME_TYPE_AS— Query dynamic types for equality - 9.226
SCALE— Scale a real value - 9.227
SCAN— Scan a string for the presence of a set of characters - 9.228
SECNDS— Time function - 9.229
SECOND— CPU time function - 9.230
SELECTED_CHAR_KIND— Choose character kind - 9.231
SELECTED_INT_KIND— Choose integer kind - 9.232
SELECTED_REAL_KIND— Choose real kind - 9.233
SET_EXPONENT— Set the exponent of the model - 9.234
SHAPE— Determine the shape of an array - 9.235
SHIFTA— Right shift with fill - 9.236
SHIFTL— Left shift - 9.237
SHIFTR— Right shift - 9.238
SIGN— Sign copying function - 9.239
SIGNAL— Signal handling subroutine (or function) - 9.240
SIN— Sine function - 9.241
SINH— Hyperbolic sine function - 9.242
SIZE— Determine the size of an array - 9.243
SIZEOF— Size in bytes of an expression - 9.244
SLEEP— Sleep for the specified number of seconds - 9.245
SPACING— Smallest distance between two numbers of a given type - 9.246
SPREAD— Add a dimension to an array - 9.247
SQRT— Square-root function - 9.248
SRAND— Reinitialize the random number generator - 9.249
STAT— Get file status - 9.250
STORAGE_SIZE— Storage size in bits - 9.251
SUM— Sum of array elements - 9.252
SYMLNK— Create a symbolic link - 9.253
SYSTEM— Execute a shell command - 9.254
SYSTEM_CLOCK— Time function - 9.255
TAN— Tangent function - 9.256
TANH— Hyperbolic tangent function - 9.257
THIS_IMAGE— Function that returns the cosubscript index of this image - 9.258
TIME— Time function - 9.259
TIME8— Time function (64-bit) - 9.260
TINY— Smallest positive number of a real kind - 9.261
TRAILZ— Number of trailing zero bits of an integer - 9.262
TRANSFER— Transfer bit patterns - 9.263
TRANSPOSE— Transpose an array of rank two - 9.264
TRIM— Remove trailing blank characters of a string - 9.265
TTYNAM— Get the name of a terminal device. - 9.266
UBOUND— Upper dimension bounds of an array - 9.267
UCOBOUND— Upper codimension bounds of an array - 9.268
UMASK— Set the file creation mask - 9.269
UNLINK— Remove a file from the file system - 9.270
UNPACK— Unpack an array of rank one into an array - 9.271
VERIFY— Scan a string for characters not a given set - 9.272
XOR— Bitwise logical exclusive OR
- 10 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: | ||
| Part I: Invoking GNU Fortran | ||
|---|---|---|
| • Invoking GNU Fortran: | Command options supported by gfortran. |
|
| • Runtime: | Influencing runtime behavior with environment variables. | |
| Part II: Language Reference | ||
| • Fortran 2003 and 2008 status: | Fortran 2003 and 2008 features supported by GNU Fortran. | |
| • Compiler Characteristics: | User-visible implementation details. | |
| • Extensions: | Language extensions implemented by GNU Fortran. | |
| • Mixed-Language Programming: | Interoperability with C | |
| • Coarray Programming: | ||
| • Intrinsic Procedures: | Intrinsic procedures supported by GNU Fortran. | |
| • Intrinsic Modules: | Intrinsic modules supported by GNU Fortran. | |
| • Contributing: | How you can help. | |
| • Copying: | GNU General Public License says how you can copy and share GNU Fortran. | |
| • GNU Free Documentation License: | How you can copy and share this manual. | |
| • Funding: | How to help assure continued work for free software. | |
| • Option Index: | Index of command line options | |
| • Keyword Index: | Index of concepts | |
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