cleaned awk scripts, str escape bugfix, proper use of local variables

2025-06-16 11:04:32 +02:00
parent ee02a7647b
commit 83beaa3ad5
12 changed files with 401 additions and 262 deletions
--- a/src/awk/approx.awk
+++ b/src/awk/approx.awk
@@ -1,79 +1,102 @@
+## src/awk/approx.awk
+## Generate single-line approximate information for every iCalendar argument.
+##
+## @assign collection_labels: See configuration of the current program.
+
+# Functions
+
+# parse
+# Time-zone aware parsing of the date/date-time entry at the current record.
+#
+# @local variables: dt
+# @return: date or date-time string that can be used in date (1)
 function parse(    dt) {
  # Get timezone information
-  dt = "";
  for (i=2; i<NF-1; i+=2) {
    if ($i == "TZID") {
-      dt = "TZ=\"" $(i+1) "\" ";
-      break;
+      dt = "TZ=\"" $(i+1) "\" "
+      break
    }
  }
-  # Get date/datetime
+  # Get date/date-time
  return length($NF) == 8 ?
    dt $NF :
-    dt gensub(/^([0-9]{8})T([0-9]{2})([0-9]{2})([0-9]{2})(Z)?$/, "\\1 \\2:\\3:\\4\\5", "g", $NF);
+    dt gensub(/^([0-9]{8})T([0-9]{2})([0-9]{2})([0-9]{2})(Z)?$/, "\\1 \\2:\\3:\\4\\5", "g", $NF)
 }

-function parse_duration(    dt, dta, i, n, a, seps) {
-  n = split($NF, a, /[PTWHMSD]/, seps);
-  delete dta;
+# parse_duration
+# Map iCalendar duration specification into the format to be used in date (1).
+#
+# @local variables: dt, dta, i, n, a, seps
+# @input duration: iCalendar duration string
+# @return: relative-date/date-time specification to be used in date (1)
+function parse_duration(duration,    dt, dta, i, n, a, seps) {
+  n = split(duration, a, /[PTWHMSD]/, seps)
  for (i=2; i<=n; i++) {
-    if(seps[i] == "W") dta["weeks"]   = a[i];
-    if(seps[i] == "H") dta["hours"]   = a[i];
-    if(seps[i] == "M") dta["minutes"] = a[i];
-    if(seps[i] == "S") dta["seconds"] = a[i];
-    if(seps[i] == "D") dta["days"]    = a[i];
+    if(seps[i] == "W") dta["weeks"]   = a[i]
+    if(seps[i] == "H") dta["hours"]   = a[i]
+    if(seps[i] == "M") dta["minutes"] = a[i]
+    if(seps[i] == "S") dta["seconds"] = a[i]
+    if(seps[i] == "D") dta["days"]    = a[i]
  }
-  dt = a[1] ? a[1] : "+";
-  for (i in dta) {
-    dt = dt " " dta[i] " " i;
-  }
-  return dt;
+  dt = a[1] ? a[1] : "+"
+  for (i in dta)
+    dt = dt " " dta[i] " " i
+  return dt
 }

+# fn
+# Get relative file path.
+#
+# @local variables: n, a
+# @input path: Path to file
+# @return: File path of depth 1
 function fn(path,    n, a) {
-  n = split(path, a, "/");
-  return a[n-1] "/" a[n];
+  n = split(path, a, "/")
+  return a[n-1] "/" a[n]
 }

+# title
+# Generate title string that will be displayed to user. Here, the start date
+# gets a monthly resolution.
+#
+# @input start: Parsed content of DTSTART field
+# @input summary: Content of SUMMARY field
+# @return: colorized single-line title string
 function title(start, summary) {
-  summary = substr(summary, index(summary, ":") + 1);
-  #gsub("\\\\n",    "\n", summary); # one-liner
-  #gsub("\\\\N",    "\n", summary); # one-liner
-  gsub("\\\\n",    " ",  summary);
-  gsub("\\\\N",    " ",  summary);
-  gsub("\\\\,",    ",",  summary);
-  gsub("\\\\;",    ";",  summary);
-  gsub("\\\\\\\\", "\\", summary);
-  gsub("\\|", ":", summary); # we use "|" as delimiter
-  depth = split(FILENAME, path, "/");
-  collection = depth > 1 ? path[depth-1] : "";
-  collection = collection in collection2label ? collection2label[collection] : collection;
+  summary = substr(summary, index(summary, ":") + 1)
+  gsub("\\\\n",    " ",  summary)
+  gsub("\\\\N",    " ",  summary)
+  gsub("\\\\,",    ",",  summary)
+  gsub("\\\\;",    ";",  summary)
+  gsub("\\\\\\\\", "\\", summary)
+  gsub("\\|",      ":",  summary) # we use "|" as delimiter
+  depth = split(FILENAME, path, "/")
+  collection = depth > 1 ? path[depth-1] : ""
+  collection = collection in collection2label ? collection2label[collection] : collection
  return FAINT "~ " collection " " gensub(/^[^0-9]*([0-9]{4})([0-9]{2}).*$/, "\\1-\\2", "1", start) " " summary OFF
 }

-BEGIN                 { 
-  FS="[:;=]";
-  OFS="|" 
-  split(collection_labels, mapping, ";");
+# AWK program
+BEGIN {
+  FS="[:;=]"
+  OFS="|"
+  split(collection_labels, mapping, ";")
  for (map in mapping)
  {
-    split(mapping[map], m, "=");
-    collection2label[m[1]] = m[2];
+    split(mapping[map], m, "=")
+    collection2label[m[1]] = m[2]
  }
  # Colors
-  GREEN = "\033[1;32m";
-  RED = "\033[1;31m";
-  WHITE = "\033[1;97m";
-  CYAN = "\033[1;36m";
-  FAINT = "\033[2m";
-  OFF = "\033[m";
+  FAINT = "\033[2m"
+  OFF = "\033[m"
 }
 BEGINFILE             { inside = 0; rs = 0; dur = 0; summary = ""; start = "ERROR"; end = "ERROR" }
-/^END:VEVENT/         { print "~", start, dur ? start " " end : end, title(start, summary), fn(FILENAME,    n, a); nextfile }
-/^DTSTART/ && inside  { start = parse(    dt) }
-/^DTEND/ && inside    { end = parse(    dt) }
-/^DURATION/ && inside { end = parse_duration(    dt, dta, i, n, a, seps); dur = 1 }
+/^END:VEVENT/         { print "~", start, dur ? start " " end : end, title(start, summary), fn(FILENAME); nextfile }
+/^DTSTART/ && inside  { start = parse() }
+/^DTEND/ && inside    { end = parse() }
+/^DURATION/ && inside { end = parse_duration($NF); dur = 1 }
 /^[^ ]/ && rs         { rs = 0 }
-/^ / && rs            { summary = summary substr($0, 2); }
-/^SUMMARY/ && inside  { rs = 1; summary = $0; }
+/^ / && rs            { summary = summary substr($0, 2) }
+/^SUMMARY/ && inside  { rs = 1; summary = $0 }
 /^BEGIN:VEVENT/       { inside = 1 }
--- a/src/awk/calannot.awk
+++ b/src/awk/calannot.awk
@@ -1,3 +1,9 @@
+## src/awk/calannot.awk
+## Annotate monthly calendar
+##
+## @assign cur: Day-of-month to mark as `today`
+## @assign day: Day-of-month to highlight
+
 BEGIN {
  BLACK = "\033[1;30m"
  GREEN = "\033[1;32m"
--- a/src/awk/calshift.awk
+++ b/src/awk/calshift.awk
@@ -1,3 +1,7 @@
+## src/awk/calshift.awk
+## Rearrange days of a monthly output from cal (1), such that Monday is the
+## first day of the week.
+
 BEGIN { 
  ORS = ""
  W3 = "   "
--- a/src/awk/dayview.awk
+++ b/src/awk/dayview.awk
@@ -1,20 +1,69 @@
-# $s|$e|$starttime|$endtime|$fpath|$collection|$description
+## src/awk/dayview.awk
+## Generate the view of a day from lines of the form
+## ```
+##  <start_date>|<end_date>|<start_time>|<end_time>|<file_path>|<collection>|<description>
+## ```.
+##
+## @assign today: Date of `today` in the format %D (%m/%d/%y)
+## @assign daystart: Hour of start of the day
+## @assign dayend: Hour of end of the day
+
+# Functions
+
+# allday
+# Return line for all-day event.
+#
+# @input collection: Collection symbol
+# @input desc: Event description
+# @return: Single-line string
 function allday(collection, desc) {
  return collection " " ITALIC FAINT "    (allday)    " OFF desc
 }
+
+# endstoday
+# Return line for multi-day event, or event that starts at midnight, which ends today.
+#
+# @input stop: Time at which the event ends
+# @input collection: Collection symbol
+# @input desc: Event description
+# @return: Single-line string
 function endstoday(stop, collection, desc) {
  return collection " " CYAN "      -- " stop OFF ": " desc
 }
+
+# slice
+# Return line for event that starts sometime today.
+#
+# @input start: Time at which the event starts
+# @input stop: Time at which the event ends
+# @input collection: Collection symbol
+# @input desc: Event description
+# @return: Single-line string
 function slice(start, stop, collection, desc) {
  if (stop == "00:00")
    return collection " " CYAN start " --      " OFF ": " desc
  else
    return collection " " CYAN start OFF " -- " CYAN stop OFF ": " desc
 }
+
+# hrline
+# Print line for a single hour entry.
+#
+# @input hour: Hour of the entry
 function hrline(hour) {
  hour = hour < 10 ? "0"hour : hour
  print today, hour, "", "", "", "   " FAINT hour ":00           ----------------------" OFF
 }
+
+# hrlines
+# Print lines for hour entries before an event that starts at `start` and stops
+# at `stop`.
+#
+# @local variables: starth, stoph, tmp, i
+# @input start: Time at which the event starts
+# @input stop: Time at which the event ends
+# @input h: Last event-free hour
+# @return: Hour of now last event-free hour
 function hrlines(start, stop, h,    starth, stoph, tmp, i) {
  starth = substr(start, 1, 2)
  stoph = substr(stop, 1, 2)
@@ -27,11 +76,10 @@ function hrlines(start, stop, h,    starth, stoph, tmp, i) {
  else
    return stoph + tmp
 }
+
+# AWK program
 BEGIN {
  FS = "|"
-  GREEN = "\033[1;32m"
-  RED = "\033[1;31m"
-  WHITE = "\033[1;97m"
  CYAN = "\033[1;36m"
  ITALIC = "\033[3m"
  FAINT = "\033[2m"
@@ -41,9 +89,7 @@ BEGIN {
 $1 == "00:00" && $2 == "00:00" { print today, $1, $3, $4, $5, allday($6, $7);        next }
 $1 == "00:00"                  { print today, $1, $3, $4, $5, endstoday($2, $6, $7); next }
 $1 ~ /^[0-9]{2}:[0-9]{2}$/     {
-  daystart = hrlines($1, $2, daystart,    starth, stoph, tmp, i)
+  daystart = hrlines($1, $2, daystart)
  print today, $1, $3, $4, $5, slice($1, $2, $6, $7)
 }
-END {
-  hrlines(dayend":00", 0, daystart,    starth, stoph, tmp, i)
-}
+END                            { hrlines(dayend":00", 0, daystart)                        }
--- a/src/awk/get.awk
+++ b/src/awk/get.awk
@@ -1,18 +1,23 @@
-# print content of field `field`
-BEGIN                     { FS = ":"; regex = "^" field; }
-/^BEGIN:VEVENT$/ { inside = 1 }
-/^END:VEVENT$/ { exit }
-$0 ~ regex                { content = $0;                    next; }
-/^ / && content           { content = content substr($0, 2); next; }
-/^[^ ]/ && content        { exit }
+## src/awk/get.awk
+## Print content of a field of an iCalendar file.
+##
+## @assign field: Field name
+
+# AWK program
+BEGIN              { FS = ":"; regex = "^" field }
+/^BEGIN:VEVENT$/   { inside = 1 }
+/^END:VEVENT$/     { exit }
+$0 ~ regex         { content = $0; next }
+/^ / && content    { content = content substr($0, 2); next }
+/^[^ ]/ && content { exit }
 END {
  if (!inside) { exit }
  # Process content line
-  content = substr(content, index(content, ":") + 1);
-  gsub("\\\\n",    "\n", content);
-  gsub("\\\\N",    "\n", content);
-  gsub("\\\\,",    ",",  content);
-  gsub("\\\\;",    ";",  content);
-  gsub("\\\\\\\\", "\\", content);
-  print content;
+  content = substr(content, index(content, ":") + 1)
+  gsub("\\\\n",    "\n", content)
+  gsub("\\\\N",    "\n", content)
+  gsub("\\\\,",    ",",  content)
+  gsub("\\\\;",    ";",  content)
+  gsub("\\\\\\\\", "\\", content)
+  print content
 }
--- a/src/awk/merge.awk
+++ b/src/awk/merge.awk
@@ -1,9 +1,15 @@
+## src/awk/merge.awk
+## Merge a file that contains pairs of lines for start and end dates of events
+## with the approximate data file, and group the iCalendar file paths according
+## to the weeks at which the events take place.
+
+# AWK program
 BEGIN { FS="|" }
 NR == FNR {
-  i = i + 1;
+  i = i + 1
  from_year[i] = $1
  from_week[i] = $2
-  getline;
+  getline
  to_year[i] = $1
  to_week[i] = $2
  next
@@ -19,9 +25,9 @@ NR == FNR {
    week[label] = week[label] " " $5
    week_i++
    if (week_i > 53) {
-      week_ = 1
+      week_i = 1
      year_i++
    }
  }
 }
-END { for (label in week) print label week[label]; }
+END { for (label in week) print label week[label] }
--- a/src/awk/new.awk
+++ b/src/awk/new.awk
@@ -1,36 +1,57 @@
+## src/awk/new.awk
+## Generate iCalendar file from markdown description.
+##
+## @assign uid: UID to use
+
+# Functions
+
+# escape
+# Escape string to be used as content in iCalendar files.
+#
+# @input str: String to escape
+# @return: Escaped string
 function escape(str)
 {
-  gsub("\\\\", "\\\\", str);
-  gsub(";",  "\\\\;",    str);
-  gsub(",",  "\\\\,",    str);
+  gsub("\\\\", "\\\\",  str)
+  gsub(";",    "\\\\;", str)
+  gsub(",",    "\\\\,", str)
+  return str
 }

+# print_fold
+# Print property with its content and fold according to the iCalendar
+# specification.
+#
+# @local variables: i, s
+# @input nameparam: Property name with optional parameters
+# @input content: Escaped content
 function print_fold(nameparam, content,    i, s)
 {
-  i = 74 - length(nameparam);
-  s = substr(content, 1, i);
-  print nameparam s;
-  s = substr(content, i+1, 73);
-  i = i + 73;
+  i = 74 - length(nameparam)
+  s = substr(content, 1, i)
+  print nameparam s
+  s = substr(content, i+1, 73)
+  i = i + 73
  while (s)
  {
-    print " " s;
-    s = substr(content, i+1, 73);
-    i = i + 73;
+    print " " s
+    s = substr(content, i+1, 73)
+    i = i + 73
  }
 }

+# AWK program
 BEGIN { 
-  FS=":"; 
-  zulu = strftime("%Y%m%dT%H%M%SZ", systime(), 1);
+  FS=":"
+  zulu = strftime("%Y%m%dT%H%M%SZ", systime(), 1)
 }
-desc { desc = desc "\\n" $0; next; }
+desc { desc = desc "\\n" $0; next }
 {
-  from = substr($0, 1, 6) == "::: |>" ? substr($0, 8) : "";
+  from = substr($0, 1, 6) == "::: |>" ? substr($0, 8) : ""
  if (!from)
    exit 1
  getline
-  to = substr($0, 1, 6) == "::: <|" ? substr($0, 8) : "";
+  to = substr($0, 1, 6) == "::: <|" ? substr($0, 8) : ""
  if (!to)
    exit 1
  getline
@@ -41,28 +62,28 @@ desc { desc = desc "\\n" $0; next; }
    exit 1
  getline # This line should be empty
  getline # First line of description
-  desc = $0;
-  next;
+  desc = $0
+  next
 }
 END {
  # Sanitize input
-  # If nanoseconds are not 0, then we assume user enterd "tomorrow" or
+  # If nanoseconds are not 0, then we assume user entered "tomorrow" or
  # something the like, and we make this a date entry, as opposed to a
  # date-time entry.
-  # Similalry, if the time is 00:00, we make this a date, as opposed to a
+  # Similarly, if the time is 00:00, we make this a date, as opposed to a
  # date-time entry.
  gsub("\"", "\\\"", from)
-  cmd = "date -d \"" from "\" +\"%N\"";
+  cmd = "date -d \"" from "\" +\"%N\""
  cmd | getline n
  close(cmd)
  n = n + 0
-  cmd = "date -d \"" from "\" +\"%H%M\"";
+  cmd = "date -d \"" from "\" +\"%H%M\""
  cmd | getline t
  close(cmd)
  t = t + 0
  if (n != 0 || t == 0) {
    from_type = "DATE"
-    cmd = "date -d \"" from "\" +\"%Y%m%d\"";
+    cmd = "date -d \"" from "\" +\"%Y%m%d\""
  } else {
    from_type = "DATE-TIME"
    cmd = "date -d \"" from "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
@@ -74,17 +95,17 @@ END {
  }
  #
  gsub("\"", "\\\"", to)
-  cmd = "date -d \"" to "\" +\"%N\"";
+  cmd = "date -d \"" to "\" +\"%N\""
  cmd | getline n
  close(cmd)
  n = n + 0
-  cmd = "date -d \"" to "\" +\"%H%M\"";
+  cmd = "date -d \"" to "\" +\"%H%M\""
  cmd | getline t
  close(cmd)
  t = t + 0
  if (n != 0 || t == 0) {
    to_type = "DATE"
-    cmd = "date -d \"" to "\" +\"%Y%m%d\"";
+    cmd = "date -d \"" to "\" +\"%Y%m%d\""
  } else {
    to_type = "DATE-TIME"
    cmd = "date -d \"" to "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
@@ -94,28 +115,28 @@ END {
  if (suc != 1) {
    exit 1
  }
-  escape(summary);
-  escape(location);
-  escape(desc);
+  summary = escape(summary)
+  location = escape(location)
+  desc = escape(desc)

  # print ical
-  print "BEGIN:VCALENDAR";
-  print "VERSION:2.0";
-  print "CALSCALE:GREGORIAN";
-  print "PRODID:-//fab//awk//EN";
+  print "BEGIN:VCALENDAR"
+  print "VERSION:2.0"
+  print "CALSCALE:GREGORIAN"
+  print "PRODID:-//fab//awk//EN"
  print "BEGIN:VEVENT"
-  print "DTSTAMP:" zulu;
-  print "UID:" uid;
-  print "CLASS:PRIVATE";
-  print "CREATED:" zulu;
-  print "SEQUENCE:1";
-  print "LAST-MODIFIED:" zulu;
-  print "STATUS:VEVENT";
+  print "DTSTAMP:" zulu
+  print "UID:" uid
+  print "CLASS:PRIVATE"
+  print "CREATED:" zulu
+  print "SEQUENCE:1"
+  print "LAST-MODIFIED:" zulu
+  print "STATUS:VEVENT"
  print "DTSTART;VALUE=" from_type ":" from
  print "DTEND;VALUE=" to_type ":" to
-  if (summary)    print_fold("SUMMARY:",     summary,       i, s);
-  if (desc)       print_fold("DESCRIPTION:", desc,          i, s);
-  if (location)   print_fold("LOCATION:",    location,      i, s);
+  if (summary)    print_fold("SUMMARY:",     summary)
+  if (desc)       print_fold("DESCRIPTION:", desc)
+  if (location)   print_fold("LOCATION:",    location)
  print "END:VEVENT"
  print "END:VCALENDAR"
 }
--- a/src/awk/parse.awk
+++ b/src/awk/parse.awk
@@ -1,46 +1,72 @@
+## src/awk/parse.awk
+## Parse iCalendar file and print its key aspects:
+## ```
+## <start> <end> <fpath> <collection> <summary>
+## ```.
+##
+## @assign collection_labels: See configuration of the current program.
+
+# Functions
+
+# parse
+# Time-zone aware parsing of the date/date-time entry at the current record.
+#
+# @local variables: dt
+# @return: date or date-time string that can be used in date (1)
 function parse(    dt) {
  # Get timezone information
-  dt = "";
  for (i=2; i<NF-1; i+=2) {
    if ($i == "TZID") {
-      dt = "TZ=\"" $(i+1) "\" ";
-      break;
+      dt = "TZ=\"" $(i+1) "\" "
+      break
    }
  }
-  # Get date/datetime
+  # Get date/date-time
  return length($NF) == 8 ?
    dt $NF :
-    dt gensub(/^([0-9]{8})T([0-9]{2})([0-9]{2})([0-9]{2})(Z)?$/, "\\1 \\2:\\3:\\4\\5", "g", $NF);
+    dt gensub(/^([0-9]{8})T([0-9]{2})([0-9]{2})([0-9]{2})(Z)?$/, "\\1 \\2:\\3:\\4\\5", "g", $NF)
 }

-function parse_duration(    dt, dta, i, n, a, seps) {
-  n = split($NF, a, /[PTWHMSD]/, seps);
-  delete dta;
+# parse_duration
+# Map iCalendar duration specification into the format to be used in date (1).
+#
+# @local variables: dt, dta, i, n, a, seps
+# @input duration: iCalendar duration string
+# @return: relative-date/date-time specification to be used in date (1)
+function parse_duration(duration,    dt, dta, i, n, a, seps) {
+  n = split(duration, a, /[PTWHMSD]/, seps)
  for (i=2; i<=n; i++) {
-    if(seps[i] == "W") dta["weeks"]   = a[i];
-    if(seps[i] == "H") dta["hours"]   = a[i];
-    if(seps[i] == "M") dta["minutes"] = a[i];
-    if(seps[i] == "S") dta["seconds"] = a[i];
-    if(seps[i] == "D") dta["days"]    = a[i];
+    if(seps[i] == "W") dta["weeks"]   = a[i]
+    if(seps[i] == "H") dta["hours"]   = a[i]
+    if(seps[i] == "M") dta["minutes"] = a[i]
+    if(seps[i] == "S") dta["seconds"] = a[i]
+    if(seps[i] == "D") dta["days"]    = a[i]
  }
-  dt = a[1] ? a[1] : "+";
-  for (i in dta) {
-    dt = dt " " dta[i] " " i;
-  }
-  return dt;
+  dt = a[1] ? a[1] : "+"
+  for (i in dta)
+    dt = dt " " dta[i] " " i
+  return dt
 }

-function print_data(start, dur, end, summary,    cmd, collection) {
-  summary = substr(summary, index(summary, ":") + 1);
-  gsub("\\\\n",    " ", summary); # one-liner
-  gsub("\\\\N",    " ", summary); # one-liner
-  gsub("\\\\,",    ",",  summary);
-  gsub("\\\\;",    ";",  summary);
-  gsub("\\\\\\\\", "\\", summary);
-  depth = split(FILENAME, path, "/");
+# print_data
+# Print string of parsed data.
+#
+# @local variables: cmd, collection, depth, path
+# @input start: Start time of event
+# @input dur: Boolean that indicates that `end` specifies a duration
+# @input end: End time of event, or event duration (see `dur`)
+# @input summary: Content of SUMMARY field of the event
+function print_data(start, dur, end, summary,    cmd, collection, depth, path) {
+  summary = substr(summary, index(summary, ":") + 1)
+  gsub("\\\\n",    " ",  summary) # one-liner
+  gsub("\\\\N",    " ",  summary) # one-liner
+  gsub("\\\\,",    ",",  summary)
+  gsub("\\\\;",    ";",  summary)
+  gsub("\\\\\\\\", "\\", summary)
+  depth = split(FILENAME, path, "/")
  fpath = path[depth-1] "/" path[depth]
-  collection = depth > 1 ? path[depth-1] : "";
-  collection = collection in collection2label ? collection2label[collection] : collection;
+  collection = depth > 1 ? path[depth-1] : ""
+  collection = collection in collection2label ? collection2label[collection] : collection
  collection = collection2label[path[depth-1]]
  end = dur ? start " " end : end
  cmd = "date -d '" start "' +\"%s\""
@@ -52,20 +78,21 @@ function print_data(start, dur, end, summary,    cmd, collection) {
  print start, end, fpath, collection, summary
 }

-BEGIN                 { 
-  FS="[:;=]";
-  split(collection_labels, mapping, ";");
+# AWK program
+BEGIN { 
+  FS="[:;=]"
+  split(collection_labels, mapping, ";")
  for (map in mapping)
  {
-    split(mapping[map], m, "=");
-    collection2label[m[1]] = m[2];
+    split(mapping[map], m, "=")
+    collection2label[m[1]] = m[2]
  }
 }
-/^END:VEVENT/ && inside { print_data(start, dur, end, summary,    cmd, collection); exit }
-/^DTSTART/ && inside  { start = parse(    dt) }
-/^DTEND/ && inside    { end = parse(    dt) }
-/^DURATION/ && inside { end = parse_duration(    dt, dta, i, n, a, seps); dur = 1 }
-/^[^ ]/ && rs { rs = 0 }
-/^ / && rs       { summary = summary substr($0, 2); }
-/^SUMMARY/ && inside  { rs = 1; summary = $0; }
-/^BEGIN:VEVENT/ { inside = 1 }
+/^END:VEVENT/ && inside { print_data(start, dur, end, summary); exit }
+/^DTSTART/ && inside    { start = parse() }
+/^DTEND/ && inside      { end = parse() }
+/^DURATION/ && inside   { end = parse_duration($NF); dur = 1 }
+/^[^ ]/ && rs           { rs = 0 }
+/^ / && rs              { summary = summary substr($0, 2) }
+/^SUMMARY/ && inside    { rs = 1; summary = $0 }
+/^BEGIN:VEVENT/         { inside = 1 }
--- a/src/awk/set.awk
+++ b/src/awk/set.awk
@@ -1,13 +1,31 @@
+## src/awk/set.awk
+## Set or replace the content of a specified field in the iCalendar file.
+##
+## @assign field: iCalendar field
+## @assign value: Content to set it to
+##
+## LIMITATION: This program does not fold long content lines.
+
+# Functions
+
+# escape
+# Escape string to be used as content.
+#
+# @input str: Content string
+# @return: Escaped string
 function escape(str)
 {
-  gsub("\\\\", "\\\\", str)
-  gsub(";",  "\\\\;",  str)
-  gsub(",",  "\\\\,",  str)
+  gsub("\\\\", "\\\\",   str)
+  gsub(";",    "\\\\;",  str)
+  gsub(",",    "\\\\,",  str)
  return str
 }
-BEGIN { FS = "[:;]"; }
+
+# AWK program
+
+BEGIN                 { FS = "[:;]" }
 /^BEGIN:VEVENT$/      { inside = 1 }
-/^END:VEVENT$/        { inside = 0 }
+/^END:VEVENT$/        { inside = 0; if (!duplic) print field ":" escape(value) }
 $1 == field && inside { con = 1; duplic = 1; print field ":" escape(value); next }
 $1 == field && duplic { con = 1; next }
 /^ / && con           { next }
--- a/src/awk/update.awk
+++ b/src/awk/update.awk
@@ -1,53 +1,68 @@
-function getcontent(content_line, prop)
-{
-  return substr(content_line[prop], index(content_line[prop], ":") + 1);
-}
+## src/awk/update.awk
+## Update iCalendar file from markdown file.

+# Functions
+
+# escape
+# Escape string to be used as content in iCalendar files.
+#
+# @input str: String to escape
+# @return: Escaped string
 function escape(str)
 {
-  gsub("\\\\", "\\\\", str);
-  gsub(";",  "\\\\;",    str);
-  gsub(",",  "\\\\,",    str);
+  gsub("\\\\", "\\\\",  str)
+  gsub(";",    "\\\\;", str)
+  gsub(",",    "\\\\,", str)
+  return str
 }

+# print_fold
+# Print property with its content and fold according to the iCalendar
+# specification.
+#
+# @local variables: i, s
+# @input nameparam: Property name with optional parameters
+# @input content: Escaped content
 function print_fold(nameparam, content,    i, s)
 {
-  i = 74 - length(nameparam);
-  s = substr(content, 1, i);
-  print nameparam s;
-  s = substr(content, i+1, 73);
-  i = i + 73;
+  i = 74 - length(nameparam)
+  s = substr(content, 1, i)
+  print nameparam s
+  s = substr(content, i+1, 73)
+  i = i + 73
  while (s)
  {
-    print " " s;
-    s = substr(content, i+1, 73);
-    i = i + 73;
+    print " " s
+    s = substr(content, i+1, 73)
+    i = i + 73
  }
 }

+# AWK program
+
 BEGIN { 
-  FS=":";
-  zulu = strftime("%Y%m%dT%H%M%SZ", systime(), 1);
+  FS=":"
+  zulu = strftime("%Y%m%dT%H%M%SZ", systime(), 1)
 }

-ENDFILE { 
+ENDFILE {
  if (NR == FNR)
  {
-    # If nanoseconds are not 0, then we assume user enterd "tomorrow" or
+    # If nanoseconds are not 0, then we assume user entered "tomorrow" or
    # something the like, and we make this a date entry, as opposed to a
    # date-time entry.
    gsub("\"", "\\\"", from)
-    cmd = "date -d \"" from "\" +\"%N\"";
+    cmd = "date -d \"" from "\" +\"%N\""
    cmd | getline n
    close(cmd)
    n = n + 0
-    cmd = "date -d \"" from "\" +\"%H%M\"";
+    cmd = "date -d \"" from "\" +\"%H%M\""
    cmd | getline t
    close(cmd)
    t = t + 0
    if (n != 0 || t == 0) {
      from_type = "DATE"
-      cmd = "date -d \"" from "\" +\"%Y%m%d\"";
+      cmd = "date -d \"" from "\" +\"%Y%m%d\""
    } else {
      from_type = "DATE-TIME"
      cmd = "date -d \"" from "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
@@ -59,17 +74,17 @@ ENDFILE {
    }
    #
    gsub("\"", "\\\"", to)
-    cmd = "date -d \"" to "\" +\"%N\"";
+    cmd = "date -d \"" to "\" +\"%N\""
    cmd | getline n
    close(cmd)
    n = n + 0
-    cmd = "date -d \"" to "\" +\"%H%M\"";
+    cmd = "date -d \"" to "\" +\"%H%M\""
    cmd | getline t
    close(cmd)
    t = t + 0
    if (n != 0 || t == 0) {
      to_type = "DATE"
-      cmd = "date -d \"" to "\" +\"%Y%m%d\"";
+      cmd = "date -d \"" to "\" +\"%Y%m%d\""
    } else {
      to_type = "DATE-TIME"
      cmd = "date -d \"" to "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
@@ -79,19 +94,19 @@ ENDFILE {
    if (suc != 1) {
      exit 1
    }
-    escape(summary);
-    escape(location);
-    escape(desc);
+    summary = escape(summary)
+    location = escape(location)
+    desc = escape(desc)
  }
 }

-NR == FNR && desc { desc = desc "\\n" $0; next; }
+NR == FNR && desc { desc = desc "\\n" $0; next }
 NR == FNR {
-  from = substr($0, 1, 6) == "::: |>" ? substr($0, 8) : "";
+  from = substr($0, 1, 6) == "::: |>" ? substr($0, 8) : ""
  if (!from)
    exit 1
  getline
-  to = substr($0, 1, 6) == "::: <|" ? substr($0, 8) : "";
+  to = substr($0, 1, 6) == "::: <|" ? substr($0, 8) : ""
  if (!to)
    exit 1
  getline
@@ -102,24 +117,24 @@ NR == FNR {
    exit 1
  getline # This line should be empty
  getline # First line of description
-  desc = $0;
-  next;
+  desc = $0
+  next
 }

-/^BEGIN:VEVENT$/                                              { inside = 1; print; next }
-/^X-ALT-DESC/ && inside                                       { next } # drop this alternative description
-/^ / && inside                                                { next } # drop this folded line (the only content with folded lines will be updated)
+/^BEGIN:VEVENT$/        { inside = 1; print; next }
+/^X-ALT-DESC/ && inside { next } # drop this alternative description
+/^ / && inside          { next } # drop this folded line (the only content with folded lines will be updated)
 /^(DTSTART|DTEND|SUMMARY|LOCATION|CATEGORIES|DESCRIPTION|LAST-MODIFIED)/ && inside { next } # skip for now, we will write updated fields at the end
-/^SEQUENCE/ && inside                                         { seq = $2; next } # store sequence number and skip
+/^SEQUENCE/ && inside   { seq = $2; next } # store sequence number and skip
 /^END:VEVENT$/ {
  seq = seq ? seq + 1 : 1
  print "SEQUENCE:" seq
  print "LAST-MODIFIED:" zulu
  print "DTSTART;VALUE=" from_type ":" from
  print "DTEND;VALUE=" to_type ":" to
-  print_fold("SUMMARY:",     summary,       i, s)
-  print_fold("DESCRIPTION:", desc,          i, s)
-  print_fold("LOCATION:",    location,      i, s)
+  print_fold("SUMMARY:",     summary)
+  print_fold("DESCRIPTION:", desc)
+  print_fold("LOCATION:",    location)
  inside = ""
 }
 { print }
--- a/src/awk/weeks.awk
+++ b/src/awk/weeks.awk
@@ -1,44 +0,0 @@
-function parse(    dt) {
-  # Get timezone information
-  dt = "";
-  for (i=2; i<NF-1; i+=2) {
-    if ($i == "TZID") {
-      dt = "TZ=\"" $(i+1) "\" ";
-      break;
-    }
-  }
-  # Get date/datetime
-  return length($NF) == 8 ?
-    dt $NF :
-    dt gensub(/^([0-9]{8})T([0-9]{2})([0-9]{2})([0-9]{2})(Z)?$/, "\\1 \\2:\\3:\\4\\5", "g", $NF);
-}
-
-function parse_duration(    dt, dta, i, n, a, seps) {
-  n = split($NF, a, /[PTWHMSD]/, seps);
-  delete dta;
-  for (i=2; i<=n; i++) {
-    if(seps[i] == "W") dta["weeks"]   = a[i];
-    if(seps[i] == "H") dta["hours"]   = a[i];
-    if(seps[i] == "M") dta["minutes"] = a[i];
-    if(seps[i] == "S") dta["seconds"] = a[i];
-    if(seps[i] == "D") dta["days"]    = a[i];
-  }
-  dt = a[1] ? a[1] : "+";
-  for (i in dta) {
-    dt = dt " " dta[i] " " i;
-  }
-  return dt;
-}
-
-function fn(path,    n, a) {
-  n = split(path, a, "/");
-  return a[n-1] "/" a[n];
-}
-
-BEGIN                 { FS="[:;=]"; OFS="|" }
-BEGINFILE             { inside = 0; dur = 0; start = "ERROR"; end = "ERROR" }
-/^END:VEVENT/         { print start, dur ? start " " end : end, fn(FILENAME,    n, a); nextfile }
-/^DTSTART/ && inside  { start = parse(    dt) }
-/^DTEND/ && inside    { end = parse(    dt) }
-/^DURATION/ && inside { end = parse_duration(    dt, dta, i, n, a, seps); dur = 1 }
-/^BEGIN:VEVENT/       { inside = 1 }
--- a/src/awk/weekview.awk
+++ b/src/awk/weekview.awk
@@ -1,23 +1,35 @@
+## src/awk/weekview.awk
+## Print view of all appointments of the current week.
+##
+## @assign startofweek: Date of first day in the week
+
+# Functions
+
+# c
+# Compose line that will display a day in the week.
+# 
+# @return: Single-line string
 function c() {
  return CYAN substr($0, index($0, ">") + 1) OFF "  " RED "/" OFF
 }
+
+# AWK program
+
 BEGIN {
-  GREEN = "\033[1;32m";
-  RED = "\033[1;31m";
-  WHITE = "\033[1;97m";
-  CYAN = "\033[1;36m";
-  FAINT = "\033[2m";
-  OFF = "\033[m";
+  GREEN = "\033[1;32m"
+  RED = "\033[1;31m"
+  CYAN = "\033[1;36m"
+  OFF = "\033[m"
  OFS = "|"
 }
-/^[0-7] 00:00 -- 00:00/ { dayline = dayline " " c(); next }
-/^[0-7] 00:00 -- / { dayline = dayline " <--" $4 " " c(); next }
-/^[0-7] [0-9]{2}:[0-9]{2} -- 00:00/ { dayline = dayline " " $2 "→" c(); next }
+/^[0-7] 00:00 -- 00:00/                         { dayline = dayline " " c(); next }
+/^[0-7] 00:00 -- /                              { dayline = dayline " <--" $4 " " c(); next }
+/^[0-7] [0-9]{2}:[0-9]{2} -- 00:00/             { dayline = dayline " " $2 "→" c(); next }
 /^[0-7] [0-9]{2}:[0-9]{2} -- [0-9]{2}:[0-9]{2}/ { dayline = dayline " " $2 " - " $4 " " c(); next }
-/^[0-7]$/ && dayline { print "+", startofweek " +" $0-1 " days", "", dayline; }
+/^[0-7]$/ && dayline                            { print "+", startofweek " +" $0-1 " days", "", dayline }
 /^[0-7]$/ {
-  cmd = "date -d '" startofweek " +" $0 " days' +\"%a %e %b %Y\"";
-  cmd | getline dayline;
-  close(cmd);
+  cmd = "date -d '" startofweek " +" $0 " days' +\"%a %e %b %Y\""
+  cmd | getline dayline
+  close(cmd)
  dayline = GREEN dayline ":   " OFF
 }