:: String -> IO () package:base

Write a string to the standard output device putStr is implemented as hPutStr stdout. This operation may fail with the same errors, and has the same issues with concurrency, as hPutStr!

Examples

Note that the following do not put a newline.

>>> putStr "Hello, World!"
Hello, World!

>>> putStr "\0052\0042\0050"
4*2

The same as putStr, but adds a newline character. This operation may fail with the same errors, and has the same issues with concurrency, as hPutStr!

The traceIO function outputs the trace message from the IO monad. This sequences the output with respect to other IO actions.

Deprecated: Use traceIO

The traceEventIO function emits a message to the eventlog, if eventlog tracing is available and user event tracing is enabled at runtime. Compared to traceEvent, traceEventIO sequences the event with respect to other IO actions.

The traceMarkerIO function emits a marker to the eventlog, if eventlog tracing is available and user event tracing is enabled at runtime. Compared to traceMarker, traceMarkerIO sequences the event with respect to other IO actions.

unsetEnv name removes the specified environment variable from the environment of the current process. Throws IOException if name is the empty string or contains an equals sign. Beware that this function must not be executed concurrently with getEnv, lookupEnv, getEnvironment and such. One thread reading environment variables at the same time with another one modifying them can result in a segfault, see Setenv is not Thread Safe for discussion.

Like unsetEnv, but allows for the removal of blank environment variables. May throw an exception if the underlying platform doesn't support unsetting of environment variables. Beware that this function must not be executed concurrently with getEnv, lookupEnv, getEnvironment and such. One thread reading environment variables at the same time with another one modifying them can result in a segfault, see Setenv is not Thread Safe for discussion.

Deprecated: Use traceEvent or traceEventIO