ERROR(1) ERROR(1) NAME error - analyze and disperse compiler error messages SYNOPSIS error [ -n ] [ -s ] [ -q ] [ -v ] [ -t suffixlist ] [ -I ignorefile ] [ name ] DESCRIPTION _E_r_r_o_r analyzes and optionally disperses the diagnostic error messages produced by a number of compilers and language processors to the source file and line where the errors occurred. It can replace the painful, traditional methods of scribbling abbreviations of errors on paper, and permits error messages and source code to be viewed simultaneously without machinations of multiple windows in a screen editor. _E_r_r_o_r looks at the error messages, either from the specified file _n_a_m_e or from the standard input, and attempts to determine which language processor produced each error message, determines the source file and line number to which the error message refers, determines if the error message is to be ignored or not, and inserts the (possibly slightly modified) error message into the source file as a comment on the line preceding to which the line the error message refers. Error messages which can’t be categorized by language processor or content are not inserted into any file, but are sent to the standard output. _E_r_r_o_r touches source files only after all input has been read. By specifying the -q query option, the user is asked to confirm any potentially dan‐ gerous (such as touching a file) or verbose action. Otherwise _e_r_r_o_r proceeds on its merry business. If the -t touch option and associated suffix list is given, _e_r_r_o_r will restrict itself to touch only those files with suffices in the suffix list. Error also can be asked (by specifying -v) to invoke _v_i(1) on the files in which error messages were inserted; this obviates the need to remember the names of the files with errors. _E_r_r_o_r is intended to be run with its standard input connected via a pipe to the error message source. Some language processors put error messages on their standard error file; others put their messages on the standard output. Hence, both error sources should be piped together into _e_r_r_o_r_. For example, when using the _c_s_h syntax, make -s lint |& error -q -v will analyze all the error messages produced by whatever programs _m_a_k_e runs when making lint. _E_r_r_o_r knows about the error messages produced by: _m_a_k_e_, _c_c_, _c_p_p_, _c_c_o_m_, _a_s_, _l_d_, _l_i_n_t_, _p_i_, _p_c_, _f_7_7_, and _D_E_C _W_e_s_t_e_r_n _R_e_s_e_a_r_c_h _M_o_d_u_l_a_-_2_. _E_r_r_o_r knows a standard format for error messages produced by the language processors, so is sensitive to changes in these formats. For all lan‐ guages except _P_a_s_c_a_l_, error messages are restricted to be on one line. Some error messages refer to more than one line in more than one files; _e_r_r_o_r will duplicate the error message and insert it at all of the places referenced. _E_r_r_o_r will do one of six things with error messages. _s_y_n_c_h_r_o_n_i_z_e Some language processors produce short errors describing which file it is processing. _E_r_r_o_r uses these to determine the file name for languages that don’t include the file name in each error message. These synchronization messages are consumed entirely by _e_r_r_o_r_. _d_i_s_c_a_r_d Error messages from _l_i_n_t that refer to one of the two _l_i_n_t libraries, _/_u_s_r_/_l_i_b_/_l_l_i_b_-_l_c and _/_u_s_r_/_l_i_b_/_l_l_i_b_-_p_o_r_t are dis‐ carded, to prevent accidently touching these libraries. Again, these error messages are consumed entirely by _e_r_r_o_r_. _n_u_l_l_i_f_y Error messages from _l_i_n_t can be nullified if they refer to a specific function, which is known to generate diagnostics which are not interesting. Nullified error messages are not inserted into the source file, but are written to the stan‐ dard output. The names of functions to ignore are taken from either the file named _._e_r_r_o_r_r_c in the users’s home directory, or from the file named by the -I option. If the file does not exist, no error messages are nullified. If the file does exist, there must be one function name per line. _n_o_t _f_i_l_e _s_p_e_c_i_f_i_c Error messages that can’t be intuited are grouped together, and written to the standard output before any files are touched. They will not be inserted into any source file. _f_i_l_e _s_p_e_c_i_f_i_c Error message that refer to a specific file, but to no spe‐ cific line, are written to the standard output when that file is touched. _t_r_u_e _e_r_r_o_r_s Error messages that can be intuited are candidates for inser‐ tion into the file to which they refer. Only true error messages are candidates for inserting into the file they refer to. Other error messages are consumed entirely by _e_r_r_o_r or are written to the standard output. _E_r_r_o_r inserts the error messages into the source file on the line preceding the line the language pro‐ cessor found in error. Each error message is turned into a one line comment for the language, and is internally flagged with the string ‘‘###’’ at the beginning of the error, and ‘‘%%%’’ at the end of the error. This makes pattern searching for errors easier with an editor, and allows the messages to be easily removed. In addition, each error message contains the source line number for the line the message refers to. A reasonably formatted source program can be recompiled with the error messages still in it, without having the error messages them‐ selves cause future errors. For poorly formatted source programs in free format languages, such as C or Pascal, it is possible to insert a comment into another comment, which can wreak havoc with a future com‐ pilation. To avoid this, programs with comments and source on the same line should be formatted so that language statements appear before com‐ ments. Options available with _e_r_r_o_r are: -n Do _n_o_t touch any files; all error messages are sent to the stan‐ dard output. -q The user is _q_u_e_r_i_e_d whether s/he wants to touch the file. A ‘‘y’’ or ‘‘n’’ to the question is necessary to continue. Absence of the -q option implies that all referenced files (except those refer‐ ring to discarded error messages) are to be touched. -v After all files have been touched, overlay the visual editor _v_i with it set up to edit all files touched, and positioned in the first touched file at the first error. If _v_i can’t be found, try _e_x or _e_d from standard places. -t Take the following argument as a suffix list. Files whose suf‐ fixes do not appear in the suffix list are not touched. The suffix list is dot separated, and ‘‘*’’ wildcards work. Thus the suffix list: ".c.y.foo*.h" allows _e_r_r_o_r to touch files ending with ‘‘.c’’, ‘‘.y’’, ‘‘.foo*’’ and ‘‘.y’’. -s Print out _s_t_a_t_i_s_t_i_c_s regarding the error categorization. Not too useful. _E_r_r_o_r catches interrupt and terminate signals, and if in the insertion phase, will orderly terminate what it is doing. AUTHOR Robert Henry FILES ~/.errorrc function names to ignore for _l_i_n_t error messages /dev/tty user’s teletype BUGS Opens the teletype directly to do user querying. Source files with links make a new copy of the file with only one link to it. Changing a language processor’s format of error messages may cause _e_r_r_o_r to not understand the error message. _E_r_r_o_r_, since it is purely mechanical, will not filter out subsequent errors caused by ‘floodgating’ initiated by one syntactically trivial error. Humans are still much better at discarding these related errors. Pascal error messages belong after the lines affected (error puts them before). The alignment of the ‘|’ marking the point of error is also disturbed by _e_r_r_o_r_. _E_r_r_o_r was designed for work on CRT’s at reasonably high speed. It is less pleasant on slow speed terminals, and has never been used on hard‐ copy terminals. 4th Berkeley Distribution May 5, 1986 ERROR(1)