/* prerex.c -- interactive editor of prerequisite-chart descriptions Copyright (c) 2005-08 R. D. Tennent School of Computing, Queen's University, rdt@cs.queensu.ca This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* The key functions in this program are as follows: analyze_tex_file(): reads a TeX file and builds an internal representation of the boxes, arrows, and minis for the chart in linked lists accessed through global pointer variables first_box, first_arrow, and first_mini, resp. Non-chart elements of the TeX file are preserved in temporary files pretext, posttext, and comments. The Boolean variable grid records whether a background coordinate grid should be displayed. regenerate_tex_file(): re-constructs a TeX file from the temporary files pretext, posttext and comments, and the linked lists of nodes and arrows; merge_lists() implements the output-ordering strategy. analyze_user_command(): processes editing and other commands entered at the interactive prompt. The current stacks of "cuts" and "deletions" are accessed through pointer variables first_cut and first_deletion, which are global only to allow free_lists() to garbage-collect the cuts and other lists when necessary. Changelog: Version 4.1, 2008-05-16 Implement shift/raise of specified diagram elements. Eliminate unnecessary dependence on libtermcap. Version 4.0.1, 2008-02-28 Corrected txt field of struct text to have size LINE_LEN+1 Version 4.0, 2008-02-13 Test for curvatures > 100. Implement \text command. Version 3.8.1, 2007-03-17 Sleep for KILL_WAIT seconds before terminating the pdf viewer. Version I.8, 2007-02-08 Semicolon appended to most user commands suppresses regeneration and reprocessing. ^C saves to file.tex. Use quit; to exit without saving. Final processing uses latex -> dvips -> ps2pdf to produce a smaller final pdf. Attempts to display the pdf during editing using value of environment variable PDFVIEWER. Version 3.7, 2006-12-27 latex->dvips->ps2pdf processing restored as an option. Warns about quitting with unpasted cuts. Version 3.6, 2006-11-29 Corrects two minor logical errors in code for arrow deletion and box editing. Generates progress messages when analyzing/saving/processing. Re-loads after every shell escape, so we can discard the Edit command. Applies shift/raise to cut and deleted nodes. Processes tex files using pdflatex instead of latex -> dvips -> ps2pdf. Version 3.5, 2006-11-20 simpler and more flexible implementation of cut/paste, delete/undelete generate undelete messages automatic re-generation and processing after editing operation Version 3.4, 2006-11-15 deal with files that are (initially) read-only deal with attempts to cut arrows Version 3.3, 2006-11-07 preserve comment lines within the chart environment correct option-handling bug introduced in 3.0 Version 3.2, 2006-11-03 Version 3.1, 2006-10-29 introduce Edit command restore write-access to TeX file during Edit or shell-command execution try to display error message in log file if LaTeX processing fails Version 3.0, 2006-10-19 replaced calls to make file.pdf by successive calls to latex, dvips, ps2pdf removed all references to pdf viewer, user must start one him/herself replaced strncpy/cat by strlcpy/cat (my implementation of the OpenBSD functions) produce warning message for truncated course code, timetable, title Version 2.4, 2006-04-12 added undelete command no warnings using -Wall -Wextra allow for cut/paste of minis that are targets of arrow test for non-existence of source/target box/mini for new arrow handle more signals than SIGINT (such as SIGSEGV) Version 2.3, 2006-03-23 remove "which" checking of pdfviewer to allow, e.g., xpdf -remote label use geometry.sty for new blank TeX file declarations of optarg, optind moved to prerex.h Version 2.2.2, 2006-03-08 Free linked structures and readline strings. Turn grid off initially before restoring a backup. Version 2.2.1, 2006-02-18 Don't try to remove/restore access to an empty filename. Version 2.2, 2006-02-15 Inputs and outputs \begin{chart} ... \end{chart} instead of \chart{ ... } Version 2.1.1, 2006-02-13 Add designation PRIVATE ( = static) to definitions of functions and variables. Version 2.1, 2006-02-09 Trap SIGINT in order to restore write-access after ^C. Add Backup command. Version 2.0.3, 2006-02-07 New arrow should have default curvature. Version 2.0.1, 2006-02-06 Free list structures before Restoring. Version 2.0, 2006-02-03 Partition into separate modules prerex.c, inout.c, edit.c Version 1.2.2, 2006-02-02 Cleanup curvature code. Use %s to output % in regenerate_tex_file. Version 1.2.1, 2006-02-02 Allow for curved recommended and co-requisite arrows. Version 1.2.0, 2006-02-01 Restore command. Version 1.1.2, 2006-01-31 Create backup of Tex file before editing. Re-open TeX file for writing before regenerating. Version 1.1.1, 2006-01-30 TeX file read-only during editing (except when re-generating it). Version 1.1.0, 2006-01-29 Corrected use of cut stacks. Eliminated cut arrow command. Introduced delete box/mini and delete arrow. Checked for duplicate boxes, minis or arrows (e.g., when pasting). Version 1.0.5, 2006-01-28 Keep stacks of cut boxes, minis, and arrows. Version 1.0.4, 2006-01-27 Add option -p. Version 1.0.3, 2006-01-26 Replace system calls to "xpdf" by calls to pdfviewer (if defined). Version 1.0.2, 2006-01-25 Replace system call to "pdflatex filename" by call to "make filename.pdf" to provide more flexibility (e.g., LaTeX vs pdfLaTeX). Version 1.0.1, 2006-01-24 Error message for pdflatex failure now refers to filename.log. Inserted checks for lp or cp increasing too far in read_textfield and read_bracketed_textfield. Process TeX file before analyzing it (as a syntax sanity pre-check). Defer arrow output if source box not previously output. */ # include "prerex.h" char *pdfviewer; element *first_node; element *first_arrow; element *first_cut; /* stack of cut nodes */ element *first_deletion; /* stack of deleted nodes/arrows */ bool grid; /* true if coordinate grid should be shown in background */ bool useLatex = false; /* true if latex -> dvips -> ps2pdf should be used */ bool reprocess = true; /* false if regenerate_and_process should do nothing */ char line[LINE_LEN]; char *command_line; char *lp; /* pointer into line or command_line */ char *cp; /* pointer into text fields */ char filename[FILE_LEN]; FILE * tex_file, *pretext, /* whatever is in the tex_file before the chart */ *posttext, /* whatever is in the tex_file after the chart */ *comments; /* comment lines in the chart environment */ char backup_filename[FILE_LEN + 1]; FILE *backup_tex_file; char deftext[LINE_LEN]; /* buffer for default input; set using set_deftext */ pid_t pid = 0; /* process id for pdfviewer */ void remove_write_access (void) /* to prevent interference */ { char command[64]; strlcpy (command, "chmod a-w ", sizeof (command)); strlcat (command, filename, sizeof (command)); system (command); } void restore_write_access (void) /* to regenerate or restore the tex_file */ { char command[64]; if (filename == NULL) return; strlcpy (command, "chmod ug+w ", sizeof (command)); strlcat (command, filename, sizeof (command)); system (command); } void error (char msg[]) /* abort with stderr message msg */ { fprintf (stderr, "Error: %s\n", msg); restore_write_access (); exit (EXIT_FAILURE); } size_t strlcpy (char *dst, const char *src, size_t n) /* Copies src to dst of size n. Returns strlen(src). * If strlen(src) >= n, the string is truncated. */ { char *d = dst; const char *s = src; if (n == 0) return strlen (src); while (n > 1 && *s != '\0') { *d = *s; /* copy non-null character */ d++; s++; n--; } *d = '\0'; /* null-terminate */ while (*s != '\0') s++; /* traverse rest of src */ return s - src; } size_t strlcat (char *dst, const char *src, size_t n) /* Appends src to dst of size n. Returns strlen(dst) + strlen(src). * If strlen(dst) + strlen(src) >= n, the string is truncated. */ { char *d = dst; const char *s = src; size_t dst_length; if (n == 0) return strlen (src); while (n > 1 && *d != '\0') { d++; n--; } dst_length = d - dst; while (n > 1 && *s != '\0') { *d = *s; /* copy non-null character */ d++; s++; n--; } *d = '\0'; /* null-terminate */ while (*s != '\0') s++; /* traverse rest of src */ return dst_length + (s - src); } int set_deftext (void) /* used by readline to output defaults */ { rl_insert_text (&deftext[0]); deftext[0] = '\0'; rl_startup_hook = (rl_hook_func_t *) NULL; return 0; } PRIVATE void sigproc (int i) /* signal handler */ { i = 0; /* just to suppress a gcc warning message */ grid = false; puts(""); regenerate_tex_file(); restore_write_access (); if (pid > 0) kill(pid, SIGTERM); /* terminate pdfviewer process */ exit (0); } PRIVATE void create_blank_tex_file (void) { tex_file = fopen (filename, "w+"); if (tex_file == NULL) return; fprintf (tex_file, "%s\n", "\\documentclass{article}"); fprintf (tex_file, "%s\n", "\\usepackage{geometry}"); fprintf (tex_file, "%s\n", "\\geometry{noheadfoot, margin=0.5in}"); fprintf (tex_file, "%s\n", "\\usepackage{prerex}"); fprintf (tex_file, "%s\n", "\\begin{document}"); fprintf (tex_file, "%s\n", "\\thispagestyle{empty}"); fprintf (tex_file, "%s\n", "\\begin{chart}"); fprintf (tex_file, "%s\n", "\\grid"); fprintf (tex_file, "%s\n", "\\end{chart}"); fprintf (tex_file, "%s\n", "\\end{document}"); rewind (tex_file); } PRIVATE void open_tex_file (void) { char command[LINE_LEN]; tex_file = fopen (filename, "r+"); while (tex_file == NULL) { char code[16]; strlcpy (deftext, "y", sizeof (deftext)); rl_startup_hook = set_deftext; tex_file = fopen (filename, "r"); if (tex_file != NULL) { strlcpy (command, "This file is currently read-only; change permissions and continue (y/n)? ", sizeof (command)); command_line = readline (command); sscanf (command_line, "%15s", code); free (command_line); if (code[0] == 'y') { restore_write_access (); tex_file = fopen (filename, "r+"); continue; } } strlcpy (command, "Create new prerex file ", sizeof (deftext)); strlcat (command, filename, sizeof (command)); strlcat (command, " (y/n)? ", sizeof (command)); command_line = readline (command); sscanf (command_line, "%15s", code); free (command_line); if (code[0] == 'y') { create_blank_tex_file (); } else { if (code[0] != 'n') puts ("Response not recognized; 'n' assumed."); command_line = readline ("Enter another file name: "); sscanf (command_line, "%127s", filename); free (command_line); if (!suffix (".tex", filename)) strlcat (filename, ".tex", sizeof (filename)); tex_file = fopen (filename, "r+"); } } remove_write_access (); } void create_backup (void) { strlcpy (backup_filename, ".", sizeof (backup_filename)); strlcat (backup_filename, filename, sizeof (backup_filename)); backup_tex_file = fopen (backup_filename, "w+"); if (backup_tex_file == NULL) { puts ("Can't open backup file."); return; } copy (tex_file, backup_tex_file); fclose (backup_tex_file); } void regenerate_and_process (void) { if (!reprocess) return; regenerate_tex_file (); process_tex_file (); } void process_tex_file (void) { /* generates system calls to make file.pdf */ char command[LINE_LEN]; char filename_root[FILE_LEN + 3]; char *p; rewind (tex_file); strlcpy (filename_root, filename, sizeof (filename_root)); p = strstr (filename_root, ".tex"); *p = '\0'; if (useLatex) { printf ("Processing %s using LaTeX, dvips, and ps2pdf.\n", filename); strlcpy (command, "latex ", sizeof (command)); } else { printf ("Processing %s using pdfLaTeX.\n", filename); strlcpy (command, "pdflatex ", sizeof (command)); } strlcat (command, "-halt-on-error -interaction batchmode ", sizeof (command)); strlcat (command, filename_root, sizeof (command)); strlcat (command, " > /dev/null", sizeof (command)); if (system (command)) { /* try to display error message using PAGER or tail: */ char *pager = getenv ("PAGER"); if (pager == NULL) { puts (""); puts (" ... [log file lines deleted] "); puts (""); strlcpy (command, "tail -25 ", sizeof (command)); } else if (strcmp (pager, "more") == 0) strlcpy (command, "more +/^! ", sizeof (command)); else if (strcmp (pager, "less") == 0) strlcpy (command, "less -p^! ", sizeof (command)); else { puts (" ... [log file lines deleted] "); puts (""); strlcpy (command, "tail -n 25 ", sizeof (command)); } strlcat (command, filename_root, sizeof (command)); strlcat (command, ".log", sizeof (command)); system (command); puts ("\nProcessing failed so a PDF could not be generated."); return; } if (useLatex) { strlcpy (command, "dvips -q ", sizeof (command)); strlcat (command, filename_root, sizeof (command)); strlcat (command, " -f | ps2pdf - ", sizeof (command)); strlcat (command, filename_root, sizeof (command)); strlcat (command, ".pdf", sizeof (command)); if (system (command)) puts ("dvips | ps2pdf processing fails."); } puts(""); } void open_viewer (void) { char pdf_filename[FILE_LEN]; char *p; strlcpy (pdf_filename, filename, sizeof (pdf_filename)); p = strstr (pdf_filename, ".tex"); *p = '\0'; strlcat (pdf_filename, ".pdf", sizeof (pdf_filename)); printf ("Opening %s with %s.\n", pdf_filename, pdfviewer); pid = fork(); if (pid == 0) /* child process */ { char *argv[3] = {pdfviewer, pdf_filename, (char *) NULL}; execvp(argv[0], argv); /* the call above returns only in case of an error */ printf("%s fails to start.\n", pdfviewer); _exit (0); } else if (pid == -1) perror("fork failed"); return; } int main (int argc, char *argv[]) { int ch; const char version[] = "4.1, 2008-05-16"; char prompt[FILE_LEN + 8]; printf ("This is prerex, version %s.\n", version); ch = getopt (argc, argv, "hvl"); while (ch != -1) { switch (ch) { case 'h': usage (); exit (0); case 'v': exit (0); case 'l': useLatex = true; break; case '?': exit (EXIT_FAILURE); default: printf ("Function getopt returned character code 0%o.\n", (unsigned int) ch); exit (EXIT_FAILURE); } ch = getopt (argc, argv, "hvl"); } puts ("Copyright (c) 2005-08 R. D. Tennent"); puts ("School of Computing, Queen's University, rdt@cs.queensu.ca"); puts ("This program comes with NO WARRANTY. You can redistribute prerex and/or"); puts ("modify it under the terms of the GNU General Public License version 2."); puts (""); if (optind == argc) { puts (""); do { command_line = readline ("Please enter a file name: "); sscanf (command_line, "%127s", filename); free (command_line); } while (filename[0] == '\0'); } else strlcpy (filename, argv[optind], sizeof (filename)); if (!suffix (".tex", filename)) strlcat (filename, ".tex", sizeof (filename)); open_tex_file (); pdfviewer = getenv("PDFVIEWER"); if (pdfviewer == NULL) puts("PDFVIEWER is not defined in your environment."); pretext = tmpfile (); posttext = tmpfile (); comments = tmpfile (); first_node = NULL; first_arrow = NULL; first_cut = NULL; first_deletion = NULL; analyze_tex_file (); grid = true; /* turn on background coordinate grid */ regenerate_and_process (); if (pdfviewer) open_viewer(); create_backup (); help (); signal (SIGHUP, &sigproc); signal (SIGINT, &sigproc); signal (SIGQUIT, &sigproc); signal (SIGILL, &sigproc); signal (SIGSEGV, &sigproc); signal (SIGTERM, &sigproc); /* command processing loop: */ do { strlcpy (prompt, filename, sizeof (prompt)); strlcat (prompt, "> ", sizeof (prompt)); command_line = readline (prompt); if (command_line == NULL) break; /* EOF */ if (command_line[0] != '\0') { add_history (command_line); reprocess = true; if (suffix(";", command_line)) { /* suppress possible regeneration and processing after this command */ reprocess = false; command_line[strlen(command_line)-1] = '\0'; } analyze_user_command (); } free (command_line); } while (true); /* exit via break or call to exit or error() */ putchar ('\n'); free (command_line); grid = false; useLatex = true; regenerate_and_process (); restore_write_access (); sleep(KILL_WAIT); if (pid > 0) kill(pid, SIGTERM); /* terminate pdfviewer */ return 0; }