Copyright (C) 2000-2012 |
GNU Info (autoconf.info)Printing MessagesPrinting Messages ================= `configure' scripts need to give users running them several kinds of information. The following macros print messages in ways appropriate for each kind. The arguments to all of them get enclosed in shell double quotes, so the shell performs variable and backquote substitution on them. You can print a message containing a comma by quoting the message with the `m4' quote characters: AC_MSG_RESULT([never mind, I found the BASIC compiler]) These macros are all wrappers around the `echo' shell command. `configure' scripts should rarely need to run `echo' directly to print messages for the user. Using these macros makes it easy to change how and when each kind of message is printed; such changes need only be made to the macro definitions, and all of the callers change automatically. - Macro: AC_MSG_CHECKING (FEATURE-DESCRIPTION) Notify the user that `configure' is checking for a particular feature. This macro prints a message that starts with `checking ' and ends with `...' and no newline. It must be followed by a call to `AC_MSG_RESULT' to print the result of the check and the newline. The FEATURE-DESCRIPTION should be something like `whether the Fortran compiler accepts C++ comments' or `for c89'. This macro prints nothing if `configure' is run with the `--quiet' or `--silent' option. - Macro: AC_MSG_RESULT (RESULT-DESCRIPTION) Notify the user of the results of a check. RESULT-DESCRIPTION is almost always the value of the cache variable for the check, typically `yes', `no', or a file name. This macro should follow a call to `AC_MSG_CHECKING', and the RESULT-DESCRIPTION should be the completion of the message printed by the call to `AC_MSG_CHECKING'. This macro prints nothing if `configure' is run with the `--quiet' or `--silent' option. - Macro: AC_MSG_ERROR (ERROR-DESCRIPTION) Notify the user of an error that prevents `configure' from completing. This macro prints an error message on the standard error output and exits `configure' with a nonzero status. ERROR-DESCRIPTION should be something like `invalid value $HOME for \$HOME'. - Macro: AC_MSG_WARN (PROBLEM-DESCRIPTION) Notify the `configure' user of a possible problem. This macro prints the message on the standard error output; `configure' continues running afterward, so macros that call `AC_MSG_WARN' should provide a default (back-up) behavior for the situations they warn about. PROBLEM-DESCRIPTION should be something like `ln -s seems to make hard links'. The following two macros are an obsolete alternative to `AC_MSG_CHECKING' and `AC_MSG_RESULT'. - Macro: AC_CHECKING (FEATURE-DESCRIPTION) This macro is similar to `AC_MSG_CHECKING', except that it prints a newline after the FEATURE-DESCRIPTION. It is useful mainly to print a general description of the overall purpose of a group of feature checks, e.g., AC_CHECKING(if stack overflow is detectable) - Macro: AC_VERBOSE (RESULT-DESCRIPTION) This macro is similar to `AC_MSG_RESULT', except that it is meant to follow a call to `AC_CHECKING' instead of `AC_MSG_CHECKING'; it starts the message it prints with a tab. It is considered obsolete. automatically generated by info2www version 1.2.2.9 |