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6.6.4 System interface

Questions of system interface generally fall outside of the domain of this report. However, the following operations are important enough to deserve description here.

optional procedure: load filename

Filename should be a string naming an existing file containing Scheme source code. The ‘load’ procedure reads expressions and definitions from the file and evaluates them sequentially. It is unspecified whether the results of the expressions are printed. The ‘load’ procedure does not affect the values returned by ‘current-input-port’ and ‘current-output-port’. ‘Load’ returns an unspecified value.

Rationale: For portability, ‘load’ must operate on source files. Its operation on other kinds of files necessarily varies among implementations.

optional procedure: transcript-on filename
optional procedure: transcript-off

Filename must be a string naming an output file to be created. The effect of ‘transcript-on’ is to open the named file for output, and to cause a transcript of subsequent interaction between the user and the Scheme system to be written to the file. The transcript is ended by a call to ‘transcript-off’, which closes the transcript file. Only one transcript may be in progress at any time, though some implementations may relax this restriction. The values returned by these procedures are unspecified.