ReadString

ReadString["file"]

reads the complete contents of a file and returns it as a string.

ReadString[stream]

reads everything from a stream and returns it as a string.

ReadString[proc]

reads everything generated by an external process and returns it as a string.

ReadString[src,term]

reads until the terminator term is encountered.

Details and Options

  • ReadString[File["file"],] is also supported.
  • ReadString["file",] and ReadString[File["file",] will first open "file" for reading if it is not already open. The file will be left open unless the default terminator, EndOfFile, is used.
  • ReadString is a blocking function that by default will not return until it has read whatever it is specified to read.
  • With the option setting TimeConstraint->t, ReadString waits at most t seconds, then returns whatever it has read by that time.
  • The terminator term can be any of the following:
  • "string"literal string
    pattstring pattern
    EndOfBufferend of the buffer of available content
    EndOfFileend of the source of content (default)
  • ReadString[src] or ReadString[src,EndOfFile] reads until a stream has ended or the external process providing input has terminated.
  • If ReadString is called on a source of content that has already been exhausted, it returns EndOfFile.
  • ReadString[src,EndOfBuffer] does not block and returns whatever is already available in the input buffer.

Examples

open allclose all

Basic Examples  (2)

Read a complete file into a string:

Start the system shell process:

Write two commands into the system shell process:

Read the system shell output without blocking:

Scope  (5)

Read the first paragraph of a File object:

Start the system shell process:

Write two commands into the system shell process, then exit it:

Return the full shell process output once it has finished running:

Start the system shell process:

Write some commands into the shell process:

Read the shell process output right until the terminator is found:

Start the system shell process:

Write some commands into the shell process:

Read the process output until a given string pattern is found:

Start the system shell process:

Start the Wolfram Language from the shell:

Read the Wolfram Language output:

Enter a computation to perform:

Quit the kernel:

Quit the system shell:

Read all remaining output into a string:

Introduced in 2014
 (10.0)
 |
Updated in 2016
 (11.0)