**Note:**help and version output are generated by a naïve script which tries a few variants of

*<command> --help*,

*<command> -h*etc. to find the command's help and version info. Sometimes it gets lucky, sometimes it doesn't; if the output below looks wrong, it probably is.

### lp_solve -V (return code: 255)

Usage of lp_solve version 5.5.0.13:
lp_solve [options] [[<]input_file]
List of options:
-h prints this message
-lp read from LP file (default)
-mps read from MPS file in fixed format
-fmps read from MPS file in free format
-rpar filename read parameters from filename.
-rparopt options
options for parameter file:
-H headername: header name for parameters. By default 'Default'
-rxli xliname filename
read file with xli library
-rxlidata datafilename
data file name for xli library.
-rxliopt options
options for xli library.
-rbas filename read basis from filename.
-gbas filename guess basis with variables from filename.
-wlp filename write to LP file
-wmps filename write to MPS file in fixed format
-wfmps filename write to MPS file in free format
-wxli xliname filename
write file with xli library
-wxliopt options
options for xli library.
-wxlisol xliname filename
write solution file with xli library
-wxlisolopt options
options for xli library.
-wbas filename write basis to filename.
-wpar filename write parameters to filename.
-wparopt options
options for parameter file:
-H headername: header name for parameters. By default 'Default'
-wafter Write model after solve (useful if presolve used).
-parse_only parse input file but do not solve
-nonames Ignore variables and constraint names
-norownames Ignore constraint names
-nocolnames Ignore variable names
-min Minimize the lp problem (overrules setting in file)
-max Maximize the lp problem (overrules setting in file)
-r <value> specify max nbr of pivots between a re-inversion of the matrix
-piv <rule> specify simplex pivot rule
-piv0: Select first
-piv1: Select according to Dantzig
-piv2: Select Devex pricing from Paula Harris (default)
-piv3: Select steepest edge
These pivot rules can be combined with any of the following:
-pivf In case of Steepest Edge, fall back to DEVEX in primal.
-pivm Multiple pricing.
-piva Temporarily use First Index if cycling is detected.
-pivr Adds a small randomization effect to the selected pricer.
-pivll Scan entering/leaving columns left rather than right.
-pivla Scan entering/leaving columns alternatingly left/right.
-pivh Use Harris' primal pivot logic rather than the default.
-pivt Use true norms for Devex and Steepest Edge initializations.
-o0 Don't put objective in basis.
-o1 Put objective in basis (default).
-s <mode> <scaleloop> use automatic problem scaling.
-s0: No scaling
-s1: Geometric scaling (default)
-s2: Curtis-reid scaling
-s3: Scale to convergence using largest absolute value
-s:
-s4: Numerical range-based scaling
-s5: Scale to convergence using logarithmic mean of all values
-s6: Scale based on the simple numerical range
-s7: Scale quadratic
These scaling rules can be combined with any of the following:
-sp also do power scaling.
-si also do Integer scaling (default).
-se also do equilibration to scale to the -1..1 range (default).
-presolve presolve problem before start optimizing (rows+columns)
-presolverow presolve problem before start optimizing (rows only)
-presolvecol presolve problem before start optimizing (columns only)
-presolvel also eliminate linearly dependent rows
-presolves also convert constraints to SOSes (only SOS1 handled)
-presolver If the phase 1 solution process finds that a constraint is
redundant then this constraint is deleted
-presolvek Simplification of knapsack-type constraints through
addition of an extra variable, which also helps bound the OF
-presolveq Direct substitution of one variable in 2-element equality
constraints; this requires changes to the constraint matrix
-presolvem Merge rows
-presolvefd COLFIXDUAL
-presolvebnd Presolve bounds
-presolved Presolve duals
-presolvef Identify implied free variables (releasing their expl. bounds)
-presolveslk IMPLIEDSLK
-presolveg Reduce (tighten) coef. in integer models based on GCD argument
-presolveb Attempt to fix binary variables at one of their bounds
-presolvec Attempt to reduce coefficients in binary models
-presolverowd Idenfify and delete qualifying constraints that
are dominated by others, also fixes variables at a bound
-presolvecold Deletes variables (mainly binary), that are dominated
by others (only one can be non-zero)
-C <mode> basis crash mode
-C0: No crash basis
-C2: Most feasible basis
-C3: Least degenerate basis
-prim Prefer the primal simplex for both phases.
-dual Prefer the dual simplex for both phases.
-simplexpp Set Phase1 Primal, Phase2 Primal.
-simplexdp Set Phase1 Dual, Phase2 Primal.
-simplexpd Set Phase1 Primal, Phase2 Dual.
-simplexdd Set Phase1 Dual, Phase2 Dual.
-degen use perturbations to reduce degeneracy,
can increase numerical instability
-degenc use column check to reduce degeneracy
-degend dynamic check to reduce degeneracy
-degenf anti-degen fixedvars
-degens anti-degen stalling
-degenn anti-degen numfailure
-degenl anti-degen lostfeas
-degeni anti-degen infeasible
-degenb anti-degen B&B
-degenr anti-degen Perturbation of the working RHS at refactorization
-degenp anti-degen Limit bound flips
-trej <Trej> set minimum pivot value
-epsd <epsd> set minimum tolerance for reduced costs
-epsb <epsb> set minimum tolerance for the RHS
-epsel <epsel> set tolerance for rounding values to zero
-epsp <epsp> set the value that is used as perturbation scalar for
degenerative problems
-improve <level> iterative improvement level
-improve0: none
-improve1: Running accuracy measurement of solved equations on Bx=r
-improve2: Improve initial dual feasibility by bound flips (default)
-improve4: Low-cost accuracy monitoring in the dual
-improve8: check for primal/dual feasibility at the node level
-timeout <sec> Timeout after sec seconds when not solution found.
-bfp <filename> Set basis factorization package.
-noint Ignore integer restrictions
-e <number> specifies the tolerance which is used to determine whether a
floating point number is in fact an integer.
Should be < 0.5
-g <number>
-ga <number> specifies the absolute MIP gap for branch-and-bound.
This specifies the absolute allowed tolerance
on the object function. Can result in faster solving times.
-gr <number> specifies the relative MIP gap for branch-and-bound.
This specifies the relative allowed tolerance
on the object function. Can result in faster solving times.
-f specifies that branch-and-bound algorithm stops at first found
solution
-b <bound> specify a lower bound for the objective function
to the program. If close enough, may speed up the
calculations.
-o <value> specifies that branch-and-bound algorithm stops when objective
value is better than value
-c
-cc during branch-and-bound, take the ceiling branch first
-cf during branch-and-bound, take the floor branch first
-ca during branch-and-bound, the algorithm chooses branch
-depth <limit> set branch-and-bound depth limit
-n <solnr> specify which solution number to return
-B <rule> specify branch-and-bound rule
-B0: Select Lowest indexed non-integer column (default)
-B1: Selection based on distance from the current bounds
-B2: Selection based on the largest current bound
-B3: Selection based on largest fractional value
-B4: Simple, unweighted pseudo-cost of a variable
-B5: This is an extended pseudo-costing strategy based on minimizing
the number of integer infeasibilities
-B6: This is an extended pseudo-costing strategy based on maximizing
the normal pseudo-cost divided by the number of infeasibilities.
Similar to (the reciprocal of) a cost/benefit ratio
These branch-and-bound rules can be combined with any of the following:
-Bw WeightReverse branch-and-bound
-Bb BranchReverse branch-and-bound
-Bg Greedy branch-and-bound
-Bp PseudoCost branch-and-bound
-Bf DepthFirst branch-and-bound
-Br Randomize branch-and-bound
-BG GubMode branch-and-bound
-Bd Dynamic branch-and-bound
-Bs RestartMode branch-and-bound
-BB BreadthFirst branch-and-bound
-Bo Order variables to improve branch-and-bound performance
-Bc Do bound tightening during B&B based of reduced cost info
-Bi Initialize pseudo-costs by strong branching
-time Print CPU time to parse input and to c
Error, Unable to open input file '--version'
alculate result.
-v <level> verbose mode, gives flow through the program.
if level not provided (-v) then -v4 (NORMAL) is taken.
-v0: NEUTRAL
-v1: CRITICAL
-v2: SEVERE
-v3: IMPORTANT (default)
-v4: NORMAL
-v5: DETAILED
-v6: FULL
-t trace pivot selection
-d debug mode, all intermediate results are printed,
and the branch-and-bound decisions
-R report information while solving the model
-Db <filename> Do a generic readable data dump of key lp_solve model variables
before solve.
Principally for run difference and debugging purposes
-Da <filename> Do a generic readable data dump of key lp_solve model variables
after solve.
Principally for run difference and debugging purposes
-i print all intermediate valid solutions.
Can give you useful solutions even if the total run time
is too long
-ia print all intermediate (only non-zero values) valid solutions.
Can give you useful solutions even if the total run time
is too long
-S <detail> Print solution. If detail omitted, then -S2 is used.
-S0: Print nothing
-S1: Only objective value
-S2: Obj value+variables (default)
-S3: Obj value+variables+constraints
-S4: Obj value+variables+constraints+duals
-S5: Obj value+variables+constraints+duals+lp model
-S6: Obj value+variables+constraints+duals+lp model+scales
-S7: Obj value+variables+constraints+duals+lp model+scales+lp tableau

### lp_solve --help (return code: 255)

Usage of lp_solve version 5.5.0.13:
lp_solve [options] [[<]input_file]
List of options:
-h prints this message
-lp read from LP file (default)
-mps read from MPS file in fixed format
-fmps read from MPS file in free format
-rpar filename read parameters from filename.
-rparopt options
options for parameter file:
-H headername: header name for parameters. By default 'Default'
-rxli xliname filename
read file with xli library
-rxlidata datafilename
data file name for xli library.
-rxliopt options
options for xli library.
-rbas filename read basis from filename.
-gbas filename guess basis with variables from filename.
-wlp filename write to LP file
-wmps filename write to MPS file in fixed format
-wfmps filename write to MPS file in free format
-wxli xliname filename
write file with xli library
-wxliopt options
options for xli library.
-wxlisol xliname filename
write solution file with xli library
-wxlisolopt options
options for xli library.
-wbas filename write basis to filename.
-wpar filename write parameters to filename.
-wparopt options
options for parameter file:
-H headername: header name for parameters. By default 'Default'
-wafter Write model after solve (useful if presolve used).
-parse_only parse input file but do not solve
-nonames Ignore variables and constraint names
-norownames Ignore constraint names
-nocolnames Ignore variable names
-min Minimize the lp problem (overrules setting in file)
-max Maximize the lp problem (overrules setting in file)
-r <value> specify max nbr of pivots between a re-inversion of the matrix
-piv <rule> specify simplex pivot rule
-piv0: Select first
-piv1: Select according to Dantzig
-piv2: Select Devex pricing from Paula Harris (default)
-piv3: Select steepest edge
These pivot rules can be combined with any of the following:
-pivf In case of Steepest Edge, fall back to DEVEX in primal.
-pivm Multiple pricing.
-piva Temporarily use First Index if cycling is detected.
-pivr Adds a small randomization effect to the selected pricer.
-pivll Scan entering/leaving columns left rather than right.
-pivla Scan entering/leaving columns alternatingly left/right.
-pivh Use Harris' primal pivot logic rather than the default.
-pivt Use true norms for Devex and Steepest Edge initializations.
-o0 Don't put objective in basis.
-o1 Put objective in basis (default).
-s <mode> <scaleloop> use automatic problem scaling.
-s0: No scaling
-s1: Geometric scaling (default)
-s2: Curtis-reid scaling
-s3: Scale to convergence using largest absolute value
-s:
-s4: Numerical range-based scaling
-s5: Scale to convergence using logarithmic mean of all values
-s6: Scale based on the simple numerical range
-s7: Scale quadratic
These scaling rules can be combined with any of the following:
-sp also do power scaling.
-si also do Integer scaling (default).
-se also do equilibration to scale to the -1..1 range (default).
-presolve presolve problem before start optimizing (rows+columns)
-presolverow presolve problem before start optimizing (rows only)
-presolvecol presolve problem before start optimizing (columns only)
-presolvel also eliminate linearly dependent rows
-presolves also convert constraints to SOSes (only SOS1 handled)
-presolver If the phase 1 solution process finds that a constraint is
redundant then this constraint is deleted
-presolvek Simplification of knapsack-type constraints through
addition of an extra variable, which also helps bound the OF
-presolveq Direct substitution of one variable in 2-element equality
constraints; this requires changes to the constraint matrix
-presolvem Merge rows
-presolvefd COLFIXDUAL
-presolvebnd Presolve bounds
-presolved Presolve duals
-presolvef Identify implied free variables (releasing their expl. bounds)
-presolveslk IMPLIEDSLK
-presolveg Reduce (tighten) coef. in integer models based on GCD argument
-presolveb Attempt to fix binary variables at one of their bounds
-presolvec Attempt to reduce coefficients in binary models
-presolverowd Idenfify and delete qualifying constraints that
are dominated by others, also fixes variables at a bound
-presolvecold Deletes variables (mainly binary), that are dominated
by others (only one can be non-zero)
-C <mode> basis crash mode
-C0: No crash basis
-C2: Most feasible basis
-C3: Least degenerate basis
-prim Prefer the primal simplex for both phases.
-dual Prefer the dual simplex for both phases.
-simplexpp Set Phase1 Primal, Phase2 Primal.
-simplexdp Set Phase1 Dual, Phase2 Primal.
-simplexpd Set Phase1 Primal, Phase2 Dual.
-simplexdd Set Phase1 Dual, Phase2 Dual.
-degen use perturbations to reduce degeneracy,
can increase numerical instability
-degenc use column check to reduce degeneracy
-degend dynamic check to reduce degeneracy
-degenf anti-degen fixedvars
-degens anti-degen stalling
-degenn anti-degen numfailure
-degenl anti-degen lostfeas
-degeni anti-degen infeasible
-degenb anti-degen B&B
-degenr anti-degen Perturbation of the working RHS at refactorization
-degenp anti-degen Limit bound flips
-trej <Trej> set minimum pivot value
-epsd <epsd> set minimum tolerance for reduced costs
-epsb <epsb> set minimum tolerance for the RHS
-epsel <epsel> set tolerance for rounding values to zero
-epsp <epsp> set the value that is used as perturbation scalar for
degenerative problems
-improve <level> iterative improvement level
-improve0: none
-improve1: Running accuracy measurement of solved equations on Bx=r
-improve2: Improve initial dual feasibility by bound flips (default)
-improve4: Low-cost accuracy monitoring in the dual
-improve8: check for primal/dual feasibility at the node level
-timeout <sec> Timeout after sec seconds when not solution found.
-bfp <filename> Set basis factorization package.
-noint Ignore integer restrictions
-e <number> specifies the tolerance which is used to determine whether a
floating point number is in fact an integer.
Should be < 0.5
-g <number>
-ga <number> specifies the absolute MIP gap for branch-and-bound.
This specifies the absolute allowed tolerance
on the object function. Can result in faster solving times.
-gr <number> specifies the relative MIP gap for branch-and-bound.
This specifies the relative allowed tolerance
on the object function. Can result in faster solving times.
-f specifies that branch-and-bound algorithm stops at first found
solution
-b <bound> specify a lower bound for the objective function
to the program. If close enough, may speed up the
calculations.
-o <value> specifies that branch-and-bound algorithm stops when objective
value is better than value
-c
-cc during branch-and-bound, take the ceiling branch first
-cf during branch-and-bound, take the floor branch first
-ca during branch-and-bound, the algorithm chooses branch
-depth <limit> set branch-and-bound depth limit
-n <solnr> specify which solution number to return
-B <rule> specify branch-and-bound rule
-B0: Select Lowest indexed non-integer column (default)
-B1: Selection based on distance from the current bounds
-B2: Selection based on the largest current bound
-B3: Selection based on largest fractional value
-B4: Simple, unweighted pseudo-cost of a variable
-B5: This is an extended pseudo-costing strategy based on minimizing
the number of integer infeasibilities
-B6: This is an extended pseudo-costing strategy based on maximizing
the normal pseudo-cost divided by the number of infeasibilities.
Similar to (the reciprocal of) a cost/benefit ratio
These branch-and-bound rules can be combined with any of the following:
-Bw WeightReverse branch-and-bound
-Bb BranchReverse branch-and-bound
-Bg Greedy branch-and-bound
-Bp PseudoCost branch-and-bound
-Bf DepthFirst branch-and-bound
-Br Randomize branch-and-bound
-BG GubMode branch-and-bound
-Bd Dynamic branch-and-bound
-Bs RestartMode branch-and-bound
-BB BreadthFirst branch-and-bound
-Bo Order variables to improve branch-and-bound performance
-Bc Do bound tightening during B&B based of reduced cost info
-Bi Initialize pseudo-costs by strong branching
-time Print CPU time to parse input and to c
Error, Unable to open input file '--help'
alculate result.
-v <level> verbose mode, gives flow through the program.
if level not provided (-v) then -v4 (NORMAL) is taken.
-v0: NEUTRAL
-v1: CRITICAL
-v2: SEVERE
-v3: IMPORTANT (default)
-v4: NORMAL
-v5: DETAILED
-v6: FULL
-t trace pivot selection
-d debug mode, all intermediate results are printed,
and the branch-and-bound decisions
-R report information while solving the model
-Db <filename> Do a generic readable data dump of key lp_solve model variables
before solve.
Principally for run difference and debugging purposes
-Da <filename> Do a generic readable data dump of key lp_solve model variables
after solve.
Principally for run difference and debugging purposes
-i print all intermediate valid solutions.
Can give you useful solutions even if the total run time
is too long
-ia print all intermediate (only non-zero values) valid solutions.
Can give you useful solutions even if the total run time
is too long
-S <detail> Print solution. If detail omitted, then -S2 is used.
-S0: Print nothing
-S1: Only objective value
-S2: Obj value+variables (default)
-S3: Obj value+variables+constraints
-S4: Obj value+variables+constraints+duals
-S5: Obj value+variables+constraints+duals+lp model
-S6: Obj value+variables+constraints+duals+lp model+scales
-S7: Obj value+variables+constraints+duals+lp model+scales+lp tableau