Procedure Reference

This document lists all built-in procedures organized by domain. Each procedure shows its arity (N = exactly N arguments, N+ = N or more arguments) and a short description. Click any category heading for detailed documentation with examples.

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Numbers and Arithmetic

Procedure	Arity	Description
+	0+	Sum of all arguments (0 with no args)
-	1+	Negation (1 arg) or subtraction (2+ args)
*	0+	Product of all arguments (1 with no args)
/	1+	Reciprocal (1 arg) or division (2+ args)
quotient	2	Integer division truncated toward zero
remainder	2	Remainder after truncated division
modulo	2	Modulo (sign follows divisor)
=	2+	Numeric equality
<	2+	Monotonically increasing
>	2+	Monotonically decreasing
<=	2+	Monotonically non-decreasing
>=	2+	Monotonically non-increasing
zero?	1	True if argument is zero
positive?	1	True if argument is positive
negative?	1	True if argument is negative
abs	1	Absolute value
min	1+	Minimum of arguments
max	1+	Maximum of arguments
even?	1	True if integer is even
odd?	1	True if integer is odd
gcd	0+	Greatest common divisor
lcm	0+	Least common multiple
floor	1	Largest integer not greater than argument
ceiling	1	Smallest integer not less than argument
truncate	1	Integer part, truncated toward zero
round	1	Round to nearest integer (banker's rounding)
exact?	1	True if number is exact
inexact?	1	True if number is inexact
exact-integer?	1	True if number is an exact integer
exact	1	Convert to exact representation
inexact	1	Convert to inexact representation
exact->inexact	1	Alias for inexact
inexact->exact	1	Alias for exact
expt	2	Raise base to a power
square	1	Square of a number
sqrt	1	Square root (complex result for negative reals)
exact-integer-sqrt	1	Integer square root, returns root and remainder via values
sin	1	Sine (radians)
cos	1	Cosine (radians)
tan	1	Tangent (radians)
asin	1	Arcsine
acos	1	Arccosine
atan	1+	Arctangent (1 arg) or two-argument atan2
exp	1	Exponential (e^x)
log	1+	Natural log (1 arg) or log base b (2 args)
finite?	1	True if number is finite
infinite?	1	True if number is infinite
nan?	1	True if number is NaN
number->string	1	Convert number to string representation
string->number	1+	Parse string as number (optional radix)
floor-quotient	2	Quotient from floor division
floor-remainder	2	Remainder from floor division
floor/	2	Floor division returning quotient and remainder
truncate-quotient	2	Quotient from truncated division
truncate-remainder	2	Remainder from truncated division
truncate/	2	Truncated division returning quotient and remainder
numerator	1	Numerator of a rational (identity for integers)
denominator	1	Denominator of a rational (1 for integers)
rationalize	2	Simplest rational within tolerance
make-rectangular	2	Construct complex from real and imaginary parts
make-polar	2	Construct complex from magnitude and angle
real-part	1	Real part of a complex number
imag-part	1	Imaginary part of a complex number
magnitude	1	Magnitude (absolute value) of a complex number
angle	1	Angle (argument) of a complex number

Pairs and Lists

Procedure	Arity	Description
cons	2	Construct a pair
car	1	First element of a pair
cdr	1	Second element of a pair
set-car!	2	Mutate the car of a pair
set-cdr!	2	Mutate the cdr of a pair
list	0+	Construct a list from arguments
length	1	Length of a proper list
append	0+	Append lists together
reverse	1	Reverse a list
caar	1	(car (car x))
cadr	1	(car (cdr x))
cdar	1	(cdr (car x))
cddr	1	(cdr (cdr x))
list-ref	2	Element at index k
list-tail	2	Sublist starting at index k
list-set!	3	Set element at index k
list-copy	1	Shallow copy of a list
make-list	1+	Create list of k elements (optional fill value)
member	2+	Search by equal? (optional comparator)
memq	2	Search by eq?
memv	2	Search by eqv?
assoc	2+	Association list lookup by equal? (optional comparator)
assq	2	Association list lookup by eq?
assv	2	Association list lookup by eqv?
map	2+	Apply procedure to corresponding elements of lists
for-each	2+	Like map but for side effects only
apply	2+	Apply procedure to a list of arguments

CXR Compositions (3- and 4-level)

All 24 compositions of car and cdr up to four deep. Each takes exactly 1 argument. See Pairs and Lists for the full table.

SRFI-1 List Library

Procedure	Arity	Description
fold	3+	Left fold over one or more lists
fold-right	3+	Right fold over one or more lists
reduce	3	Like fold with identity element
reduce-right	3	Like fold-right with identity element
filter	2	Keep elements satisfying predicate
remove	2	Remove elements satisfying predicate
partition	2	Split list by predicate into two lists
find	2	First element satisfying predicate, or #f
find-tail	2	Tail starting at first element satisfying predicate
any	2+	True if predicate holds for any element
every	2+	True if predicate holds for every element
count	2+	Count elements satisfying predicate
iota	1+	Generate list of integers (count, optional start and step)
zip	1+	Transpose lists into list of lists
concatenate	1	Append a list of lists
take	2	First k elements
drop	2	All but first k elements
take-while	2	Leading elements satisfying predicate
drop-while	2	Drop leading elements satisfying predicate
filter-map	2+	Map then filter false values
append-map	2+	Map then append results
last	1	Last element of a non-empty list
last-pair	1	Last pair of a non-empty list
proper-list?	1	True if argument is a proper list
dotted-list?	1	True if argument is a dotted (improper) list
circular-list?	1	True if argument is a circular list
not-pair?	1	True if argument is not a pair
null-list?	1	True if argument is the empty list (error on non-list)
list=	2+	Compare lists element-wise with a given equality predicate
cons*	1+	Like list but last arg is the tail
xcons	2	(cons cdr car) — reversed cons
list-tabulate	2	Build list of k elements from init procedure
circular-list	1+	Build a circular list from arguments
first	1	First element (same as car)
second	1	Second element
third	1	Third element
fourth	1	Fourth element
fifth	1	Fifth element
sixth	1	Sixth element
seventh	1	Seventh element
eighth	1	Eighth element
ninth	1	Ninth element
tenth	1	Tenth element
car+cdr	1	Return car and cdr as multiple values
take-right	2	Last k elements
drop-right	2	All but last k elements
split-at	2	Split list at index k into two values
span	2	Split list at first element not satisfying predicate
break	2	Split list at first element satisfying predicate
unfold	4+	Unfold a list from a seed value
unfold-right	4+	Unfold a list in reverse from a seed value
pair-fold	3+	Fold over pairs (not elements)
pair-fold-right	3+	Right fold over pairs
pair-for-each	2+	For-each over pairs
map-in-order	2+	Map with guaranteed left-to-right evaluation
list-index	2+	Index of first element satisfying predicate
delete	2+	Remove all occurrences equal to element
delete-duplicates	1+	Remove duplicate elements
alist-cons	3	(cons (cons key value) alist)
alist-copy	1	Shallow copy of an association list
alist-delete	2+	Remove entries with matching key
lset=	2+	Set equality
lset-adjoin	2+	Add elements to a set
lset-union	2+	Set union
lset-intersection	2+	Set intersection
lset-difference	2+	Set difference
lset-xor	2+	Set symmetric difference
append-reverse	2	(append (reverse list1) list2)
length+	1	Length or #f for circular lists
unzip1	1	Unzip list of lists (first elements)
unzip2	1	Unzip list of lists (first two elements as values)

Strings

Procedure	Arity	Description
string	0+	Construct string from characters
make-string	1+	Create string of k characters (optional fill char)
string-length	1	Number of codepoints in string
string-ref	2	Character at codepoint index k
string-set!	3	Set character at codepoint index k
substring	3	Extract substring by codepoint indices
string-append	0+	Concatenate strings
string-copy	1+	Copy string (optional start and end)
string-copy!	3+	Copy into mutable string at offset
string-fill!	2+	Fill string with a character (optional start/end)
string->list	1+	Convert string to list of characters
list->string	1	Convert list of characters to string
string->symbol	1	Intern string as a symbol
symbol->string	1	Symbol name as a string
string->utf8	1	Convert string to UTF-8 bytevector
utf8->string	1	Convert UTF-8 bytevector to string
string->vector	1+	Convert string to vector of characters
string->number	1+	Parse string as number (optional radix)
number->string	1	Convert number to string
string-for-each	2+	Apply procedure to each character
string-map	2+	Map procedure over characters
string<?	2+	Lexicographic less-than
string<=?	2+	Lexicographic less-than-or-equal
string=?	2+	String equality
string>=?	2+	Lexicographic greater-than-or-equal
string>?	2+	Lexicographic greater-than

SRFI-13 String Library

Procedure	Arity	Description
string-contains	2+	Index of substring in string, or #f (optional start/end)
string-prefix?	2+	True if first string is a prefix of second (optional start/end)
string-suffix?	2+	True if first string is a suffix of second (optional start/end)
string-index	2+	Index of first char satisfying predicate/char-set (optional start/end)
string-index-right	2+	Index of last char satisfying predicate/char-set (optional start/end)
string-skip	2+	Index of first char NOT satisfying predicate/char-set (optional start/end)
string-skip-right	2+	Index of last char NOT satisfying predicate/char-set (optional start/end)
string-count	2+	Count chars satisfying predicate/char-set (optional start/end)
string-trim	1+	Remove leading chars matching predicate/char-set (optional start/end)
string-trim-right	1+	Remove trailing chars matching predicate/char-set (optional start/end)
string-trim-both	1+	Remove leading and trailing chars (optional start/end)
string-split	2	Split string by delimiter into list of strings
string-join	1+	Join list of strings with delimiter
string-concatenate	1	Concatenate a list of strings
string-take	2	First k characters
string-drop	2	All but first k characters
string-take-right	2	Last k characters
string-drop-right	2	All but last k characters
string-pad	2+	Pad string on the left to given length
string-pad-right	2+	Pad string on the right to given length
string-reverse	1+	Reverse a string (optional start/end)
string-filter	2+	Keep chars satisfying predicate/char-set (optional start/end)
string-delete	2+	Remove chars satisfying predicate/char-set (optional start/end)
string-replace	4	Replace substring by codepoint indices
string-titlecase	1+	Titlecase a string (optional start/end)
string-every	2+	True if predicate/char-set matches every char (optional start/end)
string-any	2+	True if predicate/char-set matches any char (optional start/end)
string-tabulate	2	Build string from index-to-char procedure
string-unfold	4+	Unfold a string from a seed
string-unfold-right	4+	Unfold a string in reverse from a seed

Characters

Procedure	Arity	Description
char->integer	1	Unicode codepoint as integer
integer->char	1	Character from Unicode codepoint
char<?	2+	Character less-than by codepoint
char<=?	2+	Character less-than-or-equal
char=?	2+	Character equality
char>=?	2+	Character greater-than-or-equal
char>?	2+	Character greater-than
char-alphabetic?	1	True if Unicode alphabetic
char-numeric?	1	True if Unicode numeric
char-whitespace?	1	True if Unicode whitespace
char-upper-case?	1	True if Unicode uppercase
char-lower-case?	1	True if Unicode lowercase
char-upcase	1	Convert to uppercase
char-downcase	1	Convert to lowercase
char-foldcase	1	Convert to foldcase (for case-insensitive comparison)
digit-value	1	Numeric value of digit character, or #f
char-ci<?	2+	Case-insensitive character less-than
char-ci<=?	2+	Case-insensitive character less-than-or-equal
char-ci=?	2+	Case-insensitive character equality
char-ci>=?	2+	Case-insensitive character greater-than-or-equal
char-ci>?	2+	Case-insensitive character greater-than
string-ci<?	2+	Case-insensitive string less-than
string-ci<=?	2+	Case-insensitive string less-than-or-equal
string-ci=?	2+	Case-insensitive string equality
string-ci>=?	2+	Case-insensitive string greater-than-or-equal
string-ci>?	2+	Case-insensitive string greater-than
string-upcase	1	Convert entire string to uppercase
string-downcase	1	Convert entire string to lowercase
string-foldcase	1	Foldcase entire string

Vectors

Procedure	Arity	Description
vector	0+	Construct vector from arguments
make-vector	1+	Create vector of k elements (optional fill value)
vector?	1	True if argument is a vector
vector-length	1	Number of elements
vector-ref	2	Element at index k
vector-set!	3	Set element at index k
vector->list	1+	Convert to list (optional start and end)
list->vector	1	Convert list to vector
vector->string	1	Convert vector of characters to string
vector-fill!	2	Fill vector with a value
vector-copy	1+	Copy vector (optional start and end)
vector-copy!	3+	Copy into vector at offset
vector-append	0+	Concatenate vectors
vector-for-each	2+	Apply procedure to each element
vector-map	2+	Map procedure over elements

SRFI-133 Vector Library

Procedure	Arity	Description
vector-unfold	2+	Build vector from seed function
vector-unfold-right	2+	Build vector in reverse from seed function
vector-concatenate	1	Concatenate a list of vectors
vector-any	2+	True if predicate holds for any element
vector-every	2+	True if predicate holds for every element
vector-index	2+	Index of first element satisfying predicate
vector-index-right	2+	Index of last element satisfying predicate
vector-skip	2+	Index of first element NOT satisfying predicate
vector-skip-right	2+	Index of last element NOT satisfying predicate
vector-binary-search	3	Binary search with comparator
vector-swap!	3	Swap two elements by index
vector-reverse!	1+	Reverse vector in place (optional start/end)
vector-reverse-copy	1+	Reversed copy (optional start/end)
vector-cumulate	3	Cumulative fold into new vector
vector-partition	2	Partition by predicate into two vectors
vector-count	2+	Count elements satisfying predicate
vector-fold	3+	Left fold over vector
vector-fold-right	3+	Right fold over vector
vector-map!	2+	In-place map
vector-empty?	1	True if vector has zero length
vector=	3	Element-wise equality with comparator

Bytevectors

Procedure	Arity	Description
bytevector?	1	True if argument is a bytevector
make-bytevector	1+	Create bytevector of k bytes (optional fill)
bytevector	0+	Construct bytevector from byte values
bytevector-length	1	Number of bytes
bytevector-u8-ref	2	Byte at index k
bytevector-u8-set!	3	Set byte at index k
bytevector-copy	1+	Copy bytevector (optional start and end)
bytevector-copy!	3+	Copy into bytevector at offset
bytevector-append	0+	Concatenate bytevectors
utf8->string	1+	Decode UTF-8 bytevector to string
string->utf8	1+	Encode string to UTF-8 bytevector
read-u8	0+	Read one byte from port
peek-u8	0+	Peek at next byte without consuming
write-u8	1+	Write one byte to port
u8-ready?	0+	True if a byte is available to read
read-bytevector	1+	Read k bytes into a new bytevector
read-bytevector!	1+	Read bytes into an existing bytevector
write-bytevector	1+	Write bytevector to port
open-input-bytevector	1	Open bytevector as input port
open-output-bytevector	0	Create output port backed by bytevector
get-output-bytevector	1	Get accumulated bytevector from output port

Ports and I/O

Procedure	Arity	Description
current-input-port	0	Current default input port (stdin)
current-output-port	0	Current default output port (stdout)
current-error-port	0	Current default error port (stderr)
port?	1	True if argument is a port
input-port?	1	True if port supports input
output-port?	1	True if port supports output
textual-port?	1	True if port is textual
binary-port?	1	True if port is binary
input-port-open?	1	True if input port is open
output-port-open?	1	True if output port is open
open-input-file	1	Open file for textual input
open-output-file	1	Open file for textual output
open-binary-input-file	1	Open file for binary input
open-binary-output-file	1	Open file for binary output
close-port	1	Close a port
close-input-port	1	Close an input port
close-output-port	1	Close an output port
file-exists?	1	True if file exists at path
delete-file	1	Delete a file
call-with-input-file	2	Open file, call proc, close file
call-with-output-file	2	Open file, call proc, close file
call-with-port	2	Call proc with port, close port when done
with-input-from-file	2	Parameterize current-input-port for proc
with-output-to-file	2	Parameterize current-output-port for proc
read	0+	Read a Scheme datum from port
read-char	0+	Read one character
peek-char	0+	Peek at next character without consuming
read-line	0+	Read a line as a string
read-string	1+	Read k characters as a string
char-ready?	0+	True if a character is available to read
display	1+	Write value in human-readable form
write	1+	Write value in machine-readable form (with quotes)
write-shared	1+	Write with datum labels for shared structure
write-simple	1+	Write without datum labels
write-char	1+	Write a single character
write-string	1+	Write a string (or substring)
newline	0+	Write a newline character
flush-output-port	0+	Flush output port buffer
open-input-string	1	Open string as input port
open-output-string	0	Create output port backed by string
get-output-string	1	Get accumulated string from output port
eof-object?	1	True if argument is the EOF object
eof-object	0	Return the EOF object

Control Flow

Procedure	Arity	Description
apply	2+	Apply procedure to arguments
call-with-current-continuation	1	Capture the current continuation
call/cc	1	Alias for call-with-current-continuation
call-with-escape-continuation	1	Capture a one-shot escape continuation
call/ec	1	Alias for call-with-escape-continuation
dynamic-wind	3	Install before/after thunks around a body
values	0+	Return multiple values
call-with-values	2	Pass multiple values from producer to consumer
raise	1	Raise an exception
raise-continuable	1	Raise a continuable exception
with-exception-handler	2	Install an exception handler
error	1+	Create error object and raise it
error-object?	1	True if argument is an error object
error-object-message	1	Error message string
error-object-irritants	1	List of irritant values from error
file-error?	1	True if error is a file error
read-error?	1	True if error is a read error

Type Checking and Equivalence

Procedure	Arity	Description
not	1	Boolean negation
boolean=?	2+	True if all arguments are the same boolean
eq?	2	Pointer identity
eqv?	2	Value equivalence (numbers, chars, booleans)
equal?	2	Deep structural equality
symbol=?	2+	True if all arguments are the same symbol
pair?	1	True if argument is a pair
null?	1	True if argument is the empty list
number?	1	True if argument is a number
integer?	1	True if argument is an integer
real?	1	True if argument is a real number
complex?	1	True if argument is a complex number
rational?	1	True if argument is rational
symbol?	1	True if argument is a symbol
string?	1	True if argument is a string
boolean?	1	True if argument is a boolean
char?	1	True if argument is a character
procedure?	1	True if argument is a procedure
list?	1	True if argument is a proper list
vector?	1	True if argument is a vector
bytevector?	1	True if argument is a bytevector
port?	1	True if argument is a port
hash-table?	1	True if argument is a hash table
promise?	1	True if argument is a promise
error-object?	1	True if argument is an error object

Hash Tables (SRFI-69)

Procedure	Arity	Description
make-hash-table	0+	Create a new hash table
hash-table?	1	True if argument is a hash table
hash-table-ref	2+	Look up key (optional default value)
hash-table-set!	3	Associate key with value
hash-table-delete!	2	Remove key
hash-table-exists?	2	True if key is present
hash-table-size	1	Number of key-value pairs
hash-table-keys	1	List of all keys
hash-table-values	1	List of all values
hash-table-walk	2	Call procedure on each key-value pair
hash-table->alist	1	Convert to association list
alist->hash-table	1	Convert association list to hash table
hash-table-copy	1	Shallow copy of hash table
hash-table-update!/default	4	Update value for key using procedure, with default

System and Environment

Procedure	Arity	Description
exit	0+	Exit the process (optional status code)
emergency-exit	0+	Immediate exit without cleanup
command-line	0	List of command-line arguments
get-environment-variable	1	Value of environment variable, or #f
get-environment-variables	0	Association list of all environment variables
current-second	0	Current TAI time as inexact real
current-jiffy	0	Current time in jiffies (high resolution)
jiffies-per-second	0	Number of jiffies per second
features	0	List of implementation feature identifiers
eval	1+	Evaluate expression in an environment
environment	0+	Create environment from library imports
interaction-environment	0	REPL environment with all bindings
load	1	Load and evaluate a Scheme source file
make-parameter	1+	Create a parameter object (optional converter)

Syntax Forms

Form	Description
define	Variable and function definition
lambda	Anonymous function
if	Conditional
quote	Literal datum
set!	Variable mutation
begin	Sequence of expressions
cond	Multi-branch conditional
case	Dispatch on datum equality
and	Short-circuit logical and
or	Short-circuit logical or
when	One-armed conditional with implicit begin
unless	Negated one-armed conditional
let	Local bindings
let*	Sequential local bindings
letrec	Mutually recursive bindings
letrec*	Sequential mutually recursive bindings
let-values	Destructure multiple values
let*-values	Sequential destructure multiple values
do	Iteration with step expressions
case-lambda	Arity-dispatched lambda
define-syntax	Define a macro
syntax-rules	Pattern-based macro transformer
let-syntax	Local macro bindings
letrec-syntax	Mutually recursive local macro bindings
quasiquote	Template with unquote and unquote-splicing
define-record-type	Define a record type
define-library	Define a library
import	Import library bindings
guard	Exception handling with cond clauses
delay	Create a promise (lazy thunk)
delay-force	Create an iterative promise
parameterize	Dynamically bind parameters
cond-expand	Feature-based conditional expansion

SRFI-18 Threads

Procedure	Arity	Description
current-thread	0	Current thread object
thread?	1	True if argument is a thread
make-thread	1+	Create a new thread (thunk, optional name)
thread-name	1	Thread's name
thread-specific	1	Thread's specific value
thread-specific-set!	2	Set thread's specific value
thread-start!	1	Start a thread
thread-yield!	0	Yield to the scheduler
thread-sleep!	1	Sleep for a duration
thread-terminate!	1	Terminate a thread
thread-join!	1+	Wait for thread completion (optional timeout)
mutex?	1	True if argument is a mutex
make-mutex	0+	Create a mutex (optional name)
mutex-name	1	Mutex name
mutex-specific	1	Mutex specific value
mutex-specific-set!	2	Set mutex specific value
mutex-state	1	Mutex state (locked/unlocked/owner)
mutex-lock!	1+	Lock a mutex (optional timeout/thread)
mutex-unlock!	1+	Unlock a mutex (optional condition variable/timeout)
condition-variable?	1	True if argument is a condition variable
make-condition-variable	0+	Create a condition variable (optional name)
condition-variable-name	1	Condition variable name
condition-variable-specific	1	Condition variable specific value
condition-variable-specific-set!	2	Set condition variable specific value
condition-variable-signal!	1	Wake one waiting thread
condition-variable-broadcast!	1	Wake all waiting threads
current-time	0	Current time as time object
time?	1	True if argument is a time object
time->seconds	1	Convert time to seconds
seconds->time	1	Convert seconds to time
join-timeout-exception?	1	True if exception is a join timeout
abandoned-mutex-exception?	1	True if exception is an abandoned mutex
terminated-thread-exception?	1	True if exception is a terminated thread
uncaught-exception?	1	True if exception is an uncaught exception
uncaught-exception-reason	1	Get the reason from an uncaught exception

Kaappi Extensions

FFI (Foreign Function Interface)

Procedure	Arity	Description
ffi-open	1	Open a shared library by path
ffi-fn	4	Bind a C function: (ffi-fn lib "name" '(param-types) 'return-type)
ffi-close	1	Close a shared library handle

Green Threads (Fibers)

Procedure	Arity	Description
spawn	1	Create and start a fiber running a thunk
yield	0	Yield to the fiber scheduler
fiber?	1	True if argument is a fiber
fiber-join	1	Wait for fiber completion, return its result
make-channel	0	Create a new channel
channel-send	2	Send a value on a channel
channel-receive	1	Receive a value from a channel
channel?	1	True if argument is a channel

Other Primitives

Lazy Evaluation

Procedure	Arity	Description
promise?	1	True if argument is a promise
make-promise	1	Wrap a value as an already-forced promise
force	1	Force a promise, memoizing the result

Records (Internal Primitives)

Procedure	Arity	Description
%make-record-type	2	Create a record type descriptor
%make-record	1+	Construct a record instance
%record?	2	Check if value is instance of record type
%record-ref	2	Access field by index
%record-set!	3	Mutate field by index

Random Numbers (SRFI-27)

Procedure	Arity	Description
random-integer	1	Random integer in [0, n)
random-real	0	Random real in [0, 1)

SRFI-170 Filesystem

Procedure	Arity	Description
file-info	1+	Get file metadata (optional follow-symlinks?)
file-info?	1	True if argument is a file-info object
file-info-type	1	File type as symbol (regular, directory, symlink, ...)
file-info:size	1	File size in bytes
file-info:mtime	1	Modification time
file-info:atime	1	Access time
file-info:ctime	1	Status change time
file-info:mode	1	File permission mode
file-info:nlinks	1	Number of hard links
file-info:uid	1	Owner user ID
file-info:gid	1	Owner group ID
file-info:inode	1	Inode number
file-info:device	1	Device ID
file-info:rdev	1	Device ID (for device files)
file-info:blksize	1	Block size
file-info:blocks	1	Number of blocks
file-info-directory?	1	True if file is a directory
file-info-regular?	1	True if file is a regular file
file-info-symlink?	1	True if file is a symlink
file-info-fifo?	1	True if file is a FIFO
file-info-socket?	1	True if file is a socket
file-info-device?	1	True if file is a device
create-directory	1+	Create a directory (optional mode)
delete-directory	1	Delete a directory
rename-file	2	Rename a file
create-symlink	2	Create a symbolic link
read-symlink	1	Read the target of a symbolic link
create-hard-link	2	Create a hard link
real-path	1	Resolve to canonical absolute path
set-file-mode	2	Set file permissions
truncate-file	2	Truncate file to given length
create-fifo	1+	Create a named pipe (optional mode)
set-file-owner	3	Set file owner (uid, gid)
set-file-times	1+	Set access and modification times
directory-files	1+	List files in a directory
open-directory	1+	Open a directory stream
read-directory	1	Read next entry from directory stream
close-directory	1	Close a directory stream
pid	0	Current process ID
umask	0	Current umask
set-umask!	1	Set umask
current-directory	0	Current working directory
set-current-directory!	1	Change working directory
user-uid	0	Current user ID
user-gid	0	Current group ID
user-effective-uid	0	Effective user ID
user-effective-gid	0	Effective group ID
user-supplementary-gids	0	Supplementary group IDs
nice	0+	Adjust process priority
user-info	1	Get user info by UID or username
user-info?	1	True if argument is a user-info object
user-info:name	1	User login name
user-info:uid	1	User ID
user-info:gid	1	User group ID
user-info:home-dir	1	Home directory path
user-info:shell	1	Login shell path
user-info:full-name	1	Full name (GECOS field)
group-info	1	Get group info by GID or group name
group-info?	1	True if argument is a group-info object
group-info:name	1	Group name
group-info:gid	1	Group ID
set-environment-variable!	2	Set an environment variable
delete-environment-variable!	1	Delete an environment variable
terminal?	1	True if port is connected to a terminal
posix-time	0	Current time as seconds since epoch
monotonic-time	0	Monotonic clock time
temp-file-prefix	0	Default temporary file prefix
create-temp-file	0+	Create a temporary file (optional prefix)

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