#LyX 1.6.0 created this file. For more info see http://www.lyx.org/ \lyxformat 345 \begin_document \begin_header \use_default_options false \textclass literate-article \language english \inputencoding default \font_roman default \font_sans default \font_typewriter default \font_default_family default \font_sc false \font_osf false \font_sf_scale 100 \font_tt_scale 100 \graphics default \paperfontsize default \spacing single \use_hyperref false \papersize default \use_geometry false \use_amsmath 0 \use_esint 0 \cite_engine basic \use_bibtopic false \paperorientation portrait \secnumdepth 3 \tocdepth 3 \paragraph_separation indent \defskip medskip \quotes_language english \papercolumns 1 \papersides 1 \paperpagestyle default \tracking_changes false \output_changes false \author "" \end_header \begin_body \begin_layout Title LyX and Literate Programming \begin_inset Newline newline \end_inset An example program \end_layout \begin_layout Author Edmar Wienskoski Jr. \begin_inset Newline newline \end_inset edmar-w-jr@technologist.com \begin_inset Foot status collapsed \begin_layout Plain Layout Modified by Bernard Michael Hurley bernardh@westherts.ac.uk ---- Don't blame Edmar for any errors that have crept in! \end_layout \end_inset \end_layout \begin_layout Abstract \series bold Note: \series default This example program is provided for educational use only. The functionality in this C program has been superceded by the equivalent Python code in \emph on examples/listerrors.lyx \emph default which should be installed in the LyX scripts directory. \end_layout \begin_layout Date \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash today \end_layout \end_inset \end_layout \begin_layout Standard \begin_inset CommandInset toc LatexCommand tableofcontents \end_inset \end_layout \begin_layout Section Introduction \end_layout \begin_layout Standard After typesetting a document, LyX scans the LaTeX log file looking for errors. For each error found, the line number is obtained and a error box is displayed in the LyX screen at that position. \end_layout \begin_layout Standard To use this feature to view compilation errors while working with literate documents, we need a program that filters the compilation errors and puts them in a format suitable for LyX reading it. \end_layout \begin_layout Standard In this document we present a filter that recognizes compilation error messages from noweb, gnu C, and the IBM C compiler (xlc). \end_layout \begin_layout Standard The filter is required to read from standard input, parse for error messages and copy the error messages to the standard output. During the output process, the filter must present the error messages in a format that LyX can interpret, currently, the LaTeX error message format. Of course, nothing will prevent future LyX releases from being able to read other formats as well (like gcc error messages for example). This mechanism is necessary to fully explore the literate programming tool's capabilities. \end_layout \begin_layout Section Algorithm \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int \begin_inset Newline newline \end_inset main (int argc, char **argv) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset if (argc == 2) { \begin_inset Newline newline \end_inset switch (argv[1][0]) { \begin_inset Newline newline \end_inset case 'n': \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset case 'x': \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset case 'a': \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset case 's': \begin_inset Newline newline \end_inset case 'b': \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset case 'g': \begin_inset Newline newline \end_inset default: \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } else { \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int main (int argc, char **argv); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Section Data Structures \end_layout \begin_layout Standard We resort to some global variables to allow access from several different routines. These are the buffer and related pointers used during the parse of the input. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset char buffer[200][200]; \begin_inset Newline newline \end_inset int last_buf_line; \begin_inset Newline newline \end_inset int last_err_line; \begin_inset Newline newline \end_inset int err_line; \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Section The output format \end_layout \begin_layout Standard The output format mimics the TeX error messages format. This function prints a number of lines residing in the global variable \family typewriter buffer \family default , a program name and line number. There is no special requirement on the input strings, they can be anything. \begin_inset Foot status collapsed \begin_layout Plain Layout This function has been slightly changed from EW's original to make scanning a bit easier with LaTeX::scanLogFile(). The test has been added because LyX can crash if empty lines are allowed here --- I can't figure out why! --- BMH \end_layout \end_inset \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset void \begin_inset Newline newline \end_inset output_error (int buf_size, int error_line, char *tool) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset int i; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset fprintf(stdout, "! Build Error: ==> %s ==> \backslash n", tool); \begin_inset Newline newline \end_inset fprintf(stdout, " ... \backslash n \backslash nl.%d ... \backslash n", error_line); \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset for (i=0; i>= \begin_inset Newline newline \end_inset void output_error (int buf_size, int error_line, char *tool); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Section Functions Implementation \end_layout \begin_layout Standard Both noweave and notangle routines, always output one single line for each error found, thus to scan the buffer for noweb error messages is enough to exam one input line at a time. Note that the noweb software does not provide a line error number, so all errors boxes related to noweb messages will be displayed at the beginning of the file. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset while (fgets(buffer[0], 200, stdin)) { \begin_inset Newline newline \end_inset if (noweb_try(0)) \begin_inset Newline newline \end_inset output_error(1, err_line, "noweb"); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard The examination itself is very inefficient. Unfortunately noweb doesn't have any characteristic that would help to identify one of its error messages. The solution is to collect all possible output messages in an array of strings, and turn the examination process into a linear search in this array. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset char *noweb_msgs[] = { \begin_inset Newline newline \end_inset "couldn't open file", \begin_inset Newline newline \end_inset "couldn't open temporary file", \begin_inset Newline newline \end_inset "error writing temporary file", \begin_inset Newline newline \end_inset "ill-formed option", \begin_inset Newline newline \end_inset "unknown option", \begin_inset Newline newline \end_inset "Bad format sequence", \begin_inset Newline newline \end_inset "Can't open output file", \begin_inset Newline newline \end_inset "Can't open temporary file", \begin_inset Newline newline \end_inset "Capacity exceeded:", \begin_inset Newline newline \end_inset "Ignoring unknown option -", \begin_inset Newline newline \end_inset "This can't happen:", \begin_inset Newline newline \end_inset "non-numeric line number in" \begin_inset Newline newline \end_inset }; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset char *noweb_msgs_mimic_gcc[] = { \begin_inset Newline newline \end_inset ": unescaped << in documentation chunk" \begin_inset Newline newline \end_inset }; \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard A noweb error message can be any string that contains a matching pair of < < \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset > >, or any of the above strings \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int \begin_inset Newline newline \end_inset noweb_try (int buf_line) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset char *s, *t, *b; \begin_inset Newline newline \end_inset int i; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset b = buffer[buf_line]; \begin_inset Newline newline \end_inset err_line = 0; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset for (i=0; i<1; i++) { \begin_inset Newline newline \end_inset s = (char *)strstr (b, noweb_msgs_mimic_gcc[i]); \begin_inset Newline newline \end_inset if (s != NULL) { \begin_inset Newline newline \end_inset t = (char *)strchr(buffer[buf_line], ':'); \begin_inset Newline newline \end_inset err_line = atoi(t+1); \begin_inset Newline newline \end_inset t = buffer[buf_line]; \begin_inset Newline newline \end_inset ++s; \begin_inset Newline newline \end_inset while (*(t++) = *(s++)); \begin_inset Newline newline \end_inset return 1; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset s = (char *)strstr(b, "<<"); \begin_inset Newline newline \end_inset if (s != NULL) { \begin_inset Newline newline \end_inset s = (char *)strstr(s+2, ">>"); \begin_inset Newline newline \end_inset if (s != NULL) { \begin_inset Newline newline \end_inset return 1; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } else { \begin_inset Newline newline \end_inset for (i = 0; i < 12; ++i) { \begin_inset Newline newline \end_inset s = (char *)strstr (b, noweb_msgs[i]); \begin_inset Newline newline \end_inset if (s != NULL) { \begin_inset Newline newline \end_inset return 1; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset return 0; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int noweb_try (int buf_line); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard The xlc compiler always outputs one single line for each error found, thus to scan the buffer for xlc error messages it is enough to exam one input line at a time. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset while (fgets(buffer[last_buf_line], 200, stdin)) { \begin_inset Newline newline \end_inset if (xlc_try(0)) \begin_inset Newline newline \end_inset output_error(1, err_line, "xlc"); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard A xlc error message is easy to identify. Every error message starts with a quoted string with no spaces, a comma, a space, the word \begin_inset Quotes eld \end_inset line \begin_inset Quotes erd \end_inset , a space, and some variable text. The following routine tests if a given buffer line matches this criteria: \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int \begin_inset Newline newline \end_inset xlc_try (int buf_line) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset char *s, *t; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset t = buffer[buf_line]; \begin_inset Newline newline \end_inset s = t+1; \begin_inset Newline newline \end_inset while (*s != '"' && *s != ' ' && *s != ' \backslash 0') \begin_inset Newline newline \end_inset s++; \begin_inset Newline newline \end_inset if (*t != '"' || *s != '"' || strncmp(s+1, ", line ", 7) != 0) \begin_inset Newline newline \end_inset return 0; \begin_inset Newline newline \end_inset s += 8; \begin_inset Newline newline \end_inset err_line = atoi(s); \begin_inset Newline newline \end_inset return 1; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset int xlc_try (int buf_line); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard The gcc compiler error messages are more complicated to scan. Each error can span more than one line in the buffer. The good news is that every buffer line on each error has the same pattern, and share the same line number. Thus the strategy will be to accumulate lines in the buffer while the reported line number is still the same. At the time they differ, all the accumulated lines, except the last one, will belong to one single error message, which now can be output-ed to LyX. \end_layout \begin_layout Standard Every gcc error message contains a string with no space followed by a \begin_inset Quotes eld \end_inset : \begin_inset Quotes eld \end_inset . If the next character is a space, then this line is a header of a error message and the next line will detail the line number of the source code where the error was found. Otherwise, the next thing is a integer number followed by another \begin_inset Quotes eld \end_inset : \begin_inset Quotes eld \end_inset . \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset char *s, *t; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset while (fgets(buffer[last_buf_line], 200, stdin)) { \begin_inset Newline newline \end_inset /****** Skip lines until I find an error */ \begin_inset Newline newline \end_inset s = (char *)strpbrk(buffer[last_buf_line], " :"); \begin_inset Newline newline \end_inset if (s == NULL || *s == ' ') \begin_inset Newline newline \end_inset continue; /* No gcc error found here */ \begin_inset Newline newline \end_inset do { \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset /****** OK It is an error message, get line number */ \begin_inset Newline newline \end_inset err_line = atoi(s+1); \begin_inset Newline newline \end_inset if (last_err_line == 0 || last_err_line == err_line) { \begin_inset Newline newline \end_inset last_err_line = err_line; \begin_inset Newline newline \end_inset continue; /* It's either a header or a continuation, don't output yet */ \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset /****** Completed the scan of one error message, output it to LyX */ \begin_inset Newline newline \end_inset discharge_buffer(1); \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset } while (fgets(buffer[last_buf_line], 200, stdin)); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset /****** EOF completes the scan of whatever was being scanned */ \begin_inset Newline newline \end_inset discharge_buffer(0); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset /****** Search first ":" in the error number */ \begin_inset Newline newline \end_inset s = (char *)strpbrk(buffer[last_buf_line], " :"); \begin_inset Newline newline \end_inset last_buf_line++; \begin_inset Newline newline \end_inset if (s == NULL || *s == ' ') \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset /****** Search second ":" in the error number */ \begin_inset Newline newline \end_inset t = (char *)strpbrk(s+1, " :"); \begin_inset Newline newline \end_inset if (t == NULL || *t == ' ') \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset /****** Verify if is all digits between ":" */ \begin_inset Newline newline \end_inset if (t != s+1+strspn(s+1, "0123456789")) \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset err_line = 0; \begin_inset Newline newline \end_inset discharge_buffer(1); \begin_inset Newline newline \end_inset continue; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard As we mentioned, when the scan of one gcc error message is completed everything in the buffer except the last line is one single error message. But if the scan terminates with a EOF or through finding one line that does not match the gcc error message criteria, then there is no \begin_inset Quotes eld \end_inset last line \begin_inset Quotes erd \end_inset in the buffer to be concerned with. In those cases we empty the buffer completely. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset void \begin_inset Newline newline \end_inset discharge_buffer (int save_last) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset if (last_err_line != 0) { \begin_inset Newline newline \end_inset clean_gcc_messages(); \begin_inset Newline newline \end_inset if (save_last != 0) { \begin_inset Newline newline \end_inset output_error(last_buf_line-1, last_err_line, "gcc"); \begin_inset Newline newline \end_inset strcpy (buffer[0], buffer[last_buf_line-1]); \begin_inset Newline newline \end_inset last_err_line = err_line; \begin_inset Newline newline \end_inset last_buf_line = 1; \begin_inset Newline newline \end_inset } else { \begin_inset Newline newline \end_inset ++last_buf_line; \begin_inset Newline newline \end_inset clean_gcc_messages(); \begin_inset Newline newline \end_inset output_error(last_buf_line-1, last_err_line, "gcc"); \begin_inset Newline newline \end_inset last_err_line = 0; \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset void discharge_buffer (int save_last); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard The next function \begin_inset Quotes eld \end_inset cleans \begin_inset Quotes erd \end_inset superfluous information from gcc messages, namely the name of the noweb file and the line number of the Error. \begin_inset Foot status collapsed \begin_layout Plain Layout More could be done. For instance, some way of distinguishing between gcc Errors and Warnings should be devised. \end_layout \end_inset \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset void \begin_inset Newline newline \end_inset clean_gcc_messages () \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset int index; \begin_inset Newline newline \end_inset char search [30]; \begin_inset Newline newline \end_inset char *tail, *head; \begin_inset Newline newline \end_inset int search_len = sprintf(search, ".nw:%d:", last_err_line); \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset for (index = 0; index < last_buf_line-1; index++) { \begin_inset Newline newline \end_inset tail = (char *)strstr (buffer[index], search); \begin_inset Newline newline \end_inset if ( tail == NULL) { \begin_inset Newline newline \end_inset tail = (char *) strstr (buffer[index], ".nw:"); \begin_inset Newline newline \end_inset if (tail) { \begin_inset Newline newline \end_inset tail += 4; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } else { \begin_inset Newline newline \end_inset tail += search_len; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset if (tail != NULL) { \begin_inset Newline newline \end_inset head = buffer[index]; \begin_inset Newline newline \end_inset while (*(head++) = *(tail++)); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset void clean_gcc_messages (); \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard To combine the scan of noweb error messages and xlc error messages is very simple. We just try each one for every input line: \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset while (fgets(buffer[0], 200, stdin)) { \begin_inset Newline newline \end_inset if (noweb_try(0)) \begin_inset Newline newline \end_inset output_error(1, err_line, "noweb"); \begin_inset Newline newline \end_inset else if (xlc_try(0)) \begin_inset Newline newline \end_inset output_error(1, err_line, "xlc"); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard To combine the scan of noweb error messages and gcc error messages is simple if we realize that it is not possible to find a noweb error message in the middle of a gcc error message. So we just repeat the gcc procedure and test for noweb error messages in the beginning of the scan: \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset char *s, *t; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset last_buf_line = 0; \begin_inset Newline newline \end_inset while (fgets(buffer[last_buf_line], 200, stdin)) { \begin_inset Newline newline \end_inset /****** Skip lines until I find an error */ \begin_inset Newline newline \end_inset if (last_buf_line == 0 && noweb_try(0)) { \begin_inset Newline newline \end_inset output_error(1, err_line, "noweb"); \begin_inset Newline newline \end_inset continue; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset s = (char *)strpbrk(buffer[last_buf_line], " :"); \begin_inset Newline newline \end_inset if (s == NULL || *s == ' ') \begin_inset Newline newline \end_inset continue; /* No gcc error found here */ \begin_inset Newline newline \end_inset do { \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset /****** OK It is an error, get line number */ \begin_inset Newline newline \end_inset err_line = atoi(s+1); \begin_inset Newline newline \end_inset if (last_err_line == 0 || last_err_line == err_line) { \begin_inset Newline newline \end_inset last_err_line = err_line; \begin_inset Newline newline \end_inset continue; /* It's either a header or a continuation, don't output yet */ \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset /****** Completed the scan of one error message, output it to LyX */ \begin_inset Newline newline \end_inset discharge_buffer(1); \begin_inset Newline newline \end_inset break; \begin_inset Newline newline \end_inset } while (fgets(buffer[last_buf_line], 200, stdin)); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset /****** EOF completes the scan of whatever was being scanned */ \begin_inset Newline newline \end_inset discharge_buffer(0); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Section Wrapping the code into a file \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset #include \begin_inset Newline newline \end_inset #include \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset <> \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard To build this program, we want to add the \begin_inset Quotes eld \end_inset -L \begin_inset Quotes erd \end_inset option in the tangle command to force gdb to load the file \family typewriter Literate.nw \family default instead of \family typewriter listerrors.c \family default . In accordance with this, we pass the \begin_inset Quotes eld \end_inset -g \begin_inset Quotes erd \end_inset option to gcc. \end_layout \begin_layout Scrap <>= \begin_inset Newline newline \end_inset #!/bin/sh \begin_inset Newline newline \end_inset if [ -z "$NOWEB_SOURCE" ]; then NOWEB_SOURCE=Literate.nw; fi \begin_inset Newline newline \end_inset notangle -L -Rlisterrors.c ${NOWEB_SOURCE} > listerrors.c \begin_inset Newline newline \end_inset gcc -g -o listerrors listerrors.c \begin_inset Newline newline \end_inset @ \end_layout \begin_layout Standard This project can be tangled and compiled from LyX if you set \family typewriter \backslash build_command \family default to call a generic script that always extracts a scrap named \family typewriter build-script \family default and executes it. Here is a example of such generic script: \end_layout \begin_layout LyX-Code #!/bin/sh \begin_inset Newline newline \end_inset notangle -Rbuild-script $1 | env NOWEB_SOURCE=$1 sh \end_layout \begin_layout LyX-Code \end_layout \end_body \end_document