Initial commit of source, readme, template, and license

1 files changed, 152 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..faf8a9e
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,152 @@
+/**
+ * Dailyjournal is an easy tool to log daily activities
+ * Copyright (C) 2022  Aaron Ball <nullspoon@oper.io>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+#define _XOPEN_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#define DEFAULT_EXTENSION ".md"
+
+void get_user_editor(char* editor) {
+  if(getenv("EDITOR") != NULL)
+    strcpy(editor, getenv("EDITOR"));
+  else
+    strcpy(editor, "vi");
+}
+
+int fedit(char* path) {
+  char editor[256];
+  char cmd[512];
+  get_user_editor(editor);
+  sprintf(cmd, "%s %s", editor, path);
+  return system(cmd);
+}
+
+int fexists(char* path) {
+  FILE* fd = fopen(path, "r");
+  if(!fd)
+    return 0;
+  fclose(fd);
+  return 1;
+}
+
+int safe_cp(char* src, char* dest) {
+  FILE* fdsrc = NULL;
+  FILE* fddest = NULL;
+  char c = '\0';
+
+  fdsrc = fopen(src, "r");
+  if(!fdsrc)
+    return -2;
+
+  // Open destination file for appending, juuuuust in case it already exists
+  fddest = fopen(dest, "r");
+  if(fddest) {
+    fclose(fddest);
+    fclose(fdsrc);
+    return 0;
+  }
+
+  fddest = fopen(dest, "a+");
+  if(! fddest)
+    return -2;
+
+  while((c = fgetc(fdsrc)) != EOF)
+    fputc(c, fddest);
+
+  fclose(fdsrc);
+  fclose(fddest);
+  return 0;
+}
+
+void getpath(char* base, int days, char* out, char* extension) {
+  time_t t;
+  struct tm* tmnow;
+  char filename[128];
+
+  t = time(NULL);
+  t = t + (days * 86400);
+  tmnow = localtime(&t);
+
+  strftime(filename, 256, "%F", tmnow);
+
+  sprintf(out, "%s/%s%s", base, filename, extension);
+}
+
+int env_or_default(char* buf, char* varname, char* defaultval) {
+  char* env = getenv(varname);
+  if(env == NULL) {
+    sprintf(buf, "%s", defaultval);
+    return 1;
+  }
+  sprintf(buf, "%s", env);
+  return 0;
+}
+
+int main(int argc, char* argv[]) {
+  char notepath[256]     = {'\0'};
+  char journaldir[512]   = {'\0'};
+  char templatepath[512] = {'\0'};
+  char *extension        = NULL;
+  int i = 0;
+
+  // Set default paths
+  sprintf(journaldir, "%s/%s", getenv("HOME"), "Documents/dailyjournal");
+
+  int days = 0;
+  if(argc > 1)
+    days = strtol(argv[1], NULL, 10);
+
+  // Set default values
+  env_or_default(journaldir, "DAILYJOURNAL_DIR", journaldir);
+  sprintf(templatepath, "%s/.template.md", journaldir);
+  env_or_default(templatepath, "DAILYJOURNAL_TEMPLATE", templatepath);
+
+  extension = strrchr(templatepath, '.');
+  if(!extension)
+    extension = DEFAULT_EXTENSION;
+
+  // If user requests negative days, we want to skip non-existant days. So `-2`
+  // is really "two entries ago" rather than two days ago, which could yield
+  // creating an empty historical note if one does not already exist (for
+  // example: on Monday, opening Friday's entry which is -3 days, but -1
+  // entry).
+  if(days < 0) {
+    while(days < 0) {
+      i--;
+      getpath(journaldir, i, notepath, extension);
+      if(fexists(notepath))
+        days++;
+      // Stop traversing after a year to avoid infinite loops when no notes
+      // exist (or exist very long ago)
+      if(i < -365) {
+        fprintf(stderr, "Refusing to search further back than one year\n");
+        return 1;
+      }
+    }
+  } else {
+    getpath(journaldir, days, notepath, extension);
+  }
+
+  if(safe_cp(templatepath, notepath) == -2) {
+    printf("No template found at %s\n", templatepath);
+    return 2;
+  }
+  return fedit(notepath);
+}