Generate and return failed = .false. if the value of the input environment variable name can be successfully retrieved as a trimmed string in the output argument value.
Otherwise, return failed = .true. indicating the occurrence of an error.
The functionality of the procedures under this generic interface are highly similar to that of the Fortran intrinsic get_environment_variable().
However, the procedures of this generic interface remove the burden of guessing the correct size of the output string value by try and error.
- Parameters
-
| [in] | name | : The input scalar character of default kind SK containing the name of the environment variable whose value should be retrieved from the runtime system shell.
The argument name must neither be empty nor all blank characters. |
| [out] | value | : The output allocatable scalar character of default kind SK containing the value of the environment variable name.
The output value is guaranteed to capture the full value of the environment variable name and without any trailing blanks.
The allocation status or the contents of value is undefined if a runtime error occurs.
Always check the returned value of failed before using value. |
| [in,out] | errmsg | : The input/output scalar character of default kind SK of arbitrary length type parameter.
If an error occurs, errmsg will be set to a descriptive message about the nature of the runtime error.
A length of LEN_IOMSG characters is likely sufficient to capture most error messages in full.
(optional. If missing, no error message will be output. It can be present only if failed is also present.) |
| [in] | length | : The input scalar integer of default kind IK representing the best-guess length of the output value of the environment variable.
By default, the initial length of value is 2**13 - 1 = 8197 characters. This is suitable for very long environment variables like PATH.
However, this may be too large in many other cases. If so, the user can provide a better starting guess for the length of value by setting the input argument length to a proper best guess positive integer.
(optional, default = 8191) |
- Returns
failed : The output scalar logical of default kind LK. It is .true. if and only if the process of retrieving the value of the environment variable fails at any point.
Possible calling interfaces ⛓
character(:, SK), allocatable :: value
character(255, SK) :: errmsg
logical(LK) :: failed
Generate and return failed = .false. if the value of the input environment variable name can be succe...
This module contains procedures and generic interfaces for inferring the runtime system shell type an...
- Warning
- The condition
length > 0_IK must hold.
This condition is verified only if the library is built with the preprocessor macro CHECK_ENABLED=1.
- See also
- isFailedPutEnvVar
Example usage ⛓
10 character(
255, SK) :: errmsg
= SK_
""
11 character(:, SK),
allocatable :: value
13 type(display_type) :: disp
17 call disp%show(
"if (isFailedGetEnvVar(SK_'OS', value)) then; call disp%show( 'Failed to fetch env. variable.' , deliml = SK_'''' ); else; call disp%show( value , deliml = SK_'''' ); end if")
18 if (
isFailedGetEnvVar(SK_
'OS', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
22 call disp%show(
"if (isFailedGetEnvVar(SK_'PWD', value)) then; call disp%show( 'Failed to fetch env. variable.' , deliml = SK_'''' ); else; call disp%show( value , deliml = SK_'''' ); end if")
23 if (
isFailedGetEnvVar(SK_
'PWD', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
27 call disp%show(
"if (isFailedGetEnvVar(SK_'HOME', value)) then; call disp%show( 'Failed to fetch env. variable.' , deliml = SK_'''' ); else; call disp%show( value , deliml = SK_'''' ); end if")
28 if (
isFailedGetEnvVar(SK_
'HOME', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
32 call disp%show(
"if (isFailedGetEnvVar(SK_'SHELL', value)) then; call disp%show( 'Failed to fetch env. variable.' , deliml = SK_'''' ); else; call disp%show( value , deliml = SK_'''' ); end if")
33 if (
isFailedGetEnvVar(SK_
'SHELL', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
37 call disp%show(
"if (isFailedGetEnvVar(SK_'', value, errmsg)) then; call disp%show( trim(errmsg) , deliml = SK_'''' ); else; call disp%show( value , deliml = SK_'''' ); end if")
This is a generic method of the derived type display_type with pass attribute.
This is a generic method of the derived type display_type with pass attribute.
This module contains classes and procedures for input/output (IO) or generic display operations on st...
type(display_type) disp
This is a scalar module variable an object of type display_type for general display.
This module defines the relevant Fortran kind type-parameters frequently used in the ParaMonte librar...
integer, parameter LK
The default logical kind in the ParaMonte library: kind(.true.) in Fortran, kind(....
integer, parameter IK
The default integer kind in the ParaMonte library: int32 in Fortran, c_int32_t in C-Fortran Interoper...
integer, parameter SK
The default character kind in the ParaMonte library: kind("a") in Fortran, c_char in C-Fortran Intero...
Generate and return an object of type display_type.
Example Unix compile command via Intel ifort compiler ⛓
3ifort -fpp -standard-semantics -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
Example Windows Batch compile command via Intel ifort compiler ⛓
2set PATH=..\..\..\lib;%PATH%
3ifort /fpp /standard-semantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe
Example Unix / MinGW compile command via GNU gfortran compiler ⛓
3gfortran -cpp -ffree-line-length-none -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
Example output ⛓
2if (
isFailedGetEnvVar(SK_
'OS', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
6if (
isFailedGetEnvVar(SK_
'PWD', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
7'/home/amir/git/paramonte/external/paramonted/doxygen/bld/linux/amd64/gnu/13.1.0/native/lib/mem/serial/fortran/checking/pkg/example/pm_sysShell/isFailedGetEnvVar'
10if (
isFailedGetEnvVar(SK_
'HOME', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
14if (
isFailedGetEnvVar(SK_
'SHELL', value))
then;
call disp%show(
'Failed to fetch env. variable.' , deliml
= SK_
'''' );
else;
call disp%show( value , deliml
= SK_
'''' );
end if
19'@pm_sysShell@isFailedGetEnvVarMsg(): Fortran runtime error: Zero-length string passed as name to get_environment_variable().'
Final Remarks ⛓
If you believe this algorithm or its documentation can be improved, we appreciate your contribution and help to edit this page's documentation and source file on GitHub.
For details on the naming abbreviations, see this page.
For details on the naming conventions, see this page.
This software is distributed under the MIT license with additional terms outlined below.
-
If you use any parts or concepts from this library to any extent, please acknowledge the usage by citing the relevant publications of the ParaMonte library.
-
If you regenerate any parts/ideas from this library in a programming environment other than those currently supported by this ParaMonte library (i.e., other than C, C++, Fortran, MATLAB, Python, R), please also ask the end users to cite this original ParaMonte library.
This software is available to the public under a highly permissive license.
Help us justify its continued development and maintenance by acknowledging its benefit to society, distributing it, and contributing to it.
- Copyright
- Computational Data Science Lab
- Author:
- Amir Shahmoradi, Tuesday March 7, 2017, 3:50 AM, Institute for Computational Engineering and Sciences (ICES), The University of Texas at Austin
Definition at line 426 of file pm_sysShell.F90.
1.9.3