Functions - io

createReadableChannel

Creates an in-memory channel which will reference stream of bytes.

openReadableCsvFile

Retrieves a readable CSV channel from a give file path.

openReadableFile

Retrieves a ReadableByteChannel from a given file path.

openWritableCsvFile

Retrieves a writable CSV channel from a give file path.

openWritableFile

Retrieves a WritableByteChannel from a given file path.

print

Prints any or error value(s) to the STDOUT.

println

Prints any or error value(s) to the STDOUT followed by a new line.

readln

Returns the input read from STDIN.

sprintf

Returns a formatted string using the specified format string and arguments. Following format specifiers are allowed.

b - boolean

B - boolean (ALL_CAPS)

d - int

f - float

x - hex

X - HEX (ALL_CAPS)

s - string (This specifier is applicable for any of the supported types in Ballerina. These values will be converted to their string representation.)

createReadableChannel

(byte content)

returns ReadableByteChannel | Error

Creates an in-memory channel which will reference stream of bytes.

Parameters

  • content byte
  • Content which should be exposed as channel

  • Return Type

    (ReadableByteChannel | Error)
  • ByteChannel representation to read the memory content or Error if any error occurred

openReadableCsvFile

(string path, Separator fieldSeparator, string charset, int skipHeaders)

returns ReadableCSVChannel | Error

Retrieves a readable CSV channel from a give file path.

Parameters

  • path string
  • File path which describes the location of the CSV

  • fieldSeparator Separator (default ,)
  • CSV record separator (i.e comma or tab)

  • charset string (default UTF-8)
  • Encoding characters in the file represents

  • skipHeaders int (default 0)
  • Number of headers which should be skipped

  • Return Type

    (ReadableCSVChannel | Error)
  • ReadableCSVChannel which could be used to iterate through the CSV records

openReadableFile

(string path)

returns ReadableByteChannel | Error

Retrieves a ReadableByteChannel from a given file path.

Parameters

  • path string
  • Relative/absolute path string to locate the file

  • Return Type

    (ReadableByteChannel | Error)
  • ByteChannel representation of the file resource or Error if any error occurred

openWritableCsvFile

(string path, Separator fieldSeparator, string charset, int skipHeaders)

returns WritableCSVChannel | Error

Retrieves a writable CSV channel from a give file path.

Parameters

  • path string
  • File path which describes the location of the CSV

  • fieldSeparator Separator (default ,)
  • CSV record separator (i.e comma or tab)

  • charset string (default UTF-8)
  • Encoding characters in the file represents

  • skipHeaders int (default 0)
  • Number of headers which should be skipped

  • Return Type

    (WritableCSVChannel | Error)
  • WritableCSVChannel which could be used to write CSV records or Error if any error occurred

openWritableFile

(string path, boolean append)

returns WritableByteChannel | Error

Retrieves a WritableByteChannel from a given file path.

Parameters

  • path string
  • Relative/absolute path string to locate the file

  • append boolean (default false)
  • Append to end of file.

  • Return Type

    (WritableByteChannel | Error)
  • ByteChannel representation of the file resource or Error if any error occurred

print

Prints any or error value(s) to the STDOUT.

Parameters

  • values any | error
  • The value(s) to be printed.

println

Prints any or error value(s) to the STDOUT followed by a new line.

Parameters

  • values any | error
  • The value(s) to be printed.

readln

(any a)

returns string

Returns the input read from STDIN.

Parameters

  • a any
  • Any value to be printed

  • Return Type

    (string)
  • Input read from STDIN

sprintf

(string format, any | error args)

returns string

Returns a formatted string using the specified format string and arguments. Following format specifiers are allowed.

b - boolean

B - boolean (ALL_CAPS)

d - int

f - float

x - hex

X - HEX (ALL_CAPS)

s - string (This specifier is applicable for any of the supported types in Ballerina. These values will be converted to their string representation.)

Parameters

  • format string
  • A format string

  • args any | error
  • Arguments referenced by the format specifiers in the format string.

  • Return Type

    (string)
  • Formatted string