feat(user/mw_create_subpage_navlinks.sh):Add script

- Note: For use with generating navigation links for Mediawiki
  subpages. Requires manually inserting each line into each subpage.

diff --git a/user/mw_create_subpage_navlinks.sh b/user/mw_create_subpage_navlinks.sh
new file mode 100644 (file)
index 0000000..de37365
--- /dev/null
+++ b/user/mw_create_subpage_navlinks.sh
@@ -0,0 +1,147 @@
+#!/bin/bash
+# Desc: Generates Mediawiki subpage navigation links
+# Input: file   text file with list of chapters
+#        stdin  text with list of chapters
+# Output: [[../Chapter 4|Next]], [[../Chapter 2|Previous]], [[../|Up]]
+# Version: 0.0.1
+# Attrib: Steven Baltakatei Sandoval. (2024-01-29). reboil.com
+# License: GPLv3+
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+read_input() {
+    # Note: May accept specified file or stdin, but not both
+    # Input:  arg     input text (newline delimited)
+    #         stdin   input text (newline delimited)
+    # Output: stdout  output text (newline delimited)
+    # Depends: BK-2020-03 read_stdin (v0.1.1), yell(), die()
+
+    # Parse args
+    ## Only 1 argument.
+    if [[ "$#" -gt 1 ]]; then die "FATAL:Too many arguments ($#):$*"; fi;
+    ## File specified.
+    if [[ "$#" -eq 1 ]] && [[ -f "$1" ]] && [[ ! -p /dev/stdin ]]; then
+        while read -r line; do
+            printf "%s\n" "$line";
+        done < "$1" && return 0; fi;
+    if [[ "$#" -eq 0 ]] && [[ -p /dev/stdin ]]; then
+        read_stdin && return 0; fi;
+    die "FATAL:Unknown error.";
+};
+read_stdin() {
+    # Desc: Consumes stdin; outputs as stdout lines
+    # Input: stdin (consumes)
+    # Output: stdout  (newline delimited)
+    #         return  0  stdin read
+    #         return  1  stdin not present
+    # Example: printf "foo\nbar\n" | read_stdin
+    # Depends: GNU bash (version 5.1.16), GNU Coreutils 8.32 (cat)
+    # Version: 0.1.1
+    # Attrib: Steven Baltakatei Sandoval (2024-01-29). reboil.com
+    local input_stdin output;
+
+    # Store stdin
+    if [[ -p /dev/stdin ]]; then
+        input_stdin="$(cat -)" || {
+            echo "FATAL:Error reading stdin." 1>&2; return 1; };
+    else
+        return 1;
+    fi;
+
+    # Store as output array elements
+    ## Read in stdin
+    if [[ -n $input_stdin ]]; then
+        while read -r line; do
+            output+=("$line");
+        done < <(printf "%s\n" "$input_stdin") || {
+            echo "FATAL:Error parsing stdin."; return 1; };
+    fi;
+
+    # Print to stdout
+    printf "%s\n" "${output[@]}";
+
+    return 0;
+}; # read stdin to stdout lines
+validate_subpage_list() {
+    # Desc: Check for illegal characters in subpage titles
+    # Input:  stdin   unvalidated subpage list
+    # Output: stdout  validated subpage list
+    # Depends: BK-2020-03 read_stdin(), yell(), die()
+    #          GNU sed v4.8
+    while read -r line; do
+
+        # Reject chars illegal in Mediawiki page titles.
+        re_illegal='[][><|}{#_]'; #  match illegal page names chars #, <, >, [, ], _, {, |, }
+        if [[ "$line" =~ $re_illegal ]]; then
+            die "FATAL:Illegal char. Not allowed: #, <, >, [, ], _, {, |, }:$line";
+        fi;
+
+        # Reject trailing spaces.
+        re_ts=' $';  # match trailing space
+        if [[ "$line" =~ $re_ts ]]; then
+            die "FATAL:Trailing spaces not allowed:$line";
+        fi;
+
+        # Replace some chars with HTML-style codes
+        ## replace ampersand    & with &#38  # must be first
+        ## replace double quote " with &#34
+        ## replace single quote ' with &#39
+        line="$(sed \
+                  -e 's/&/\&#38;/g' \
+                  -e 's/"/\&#34;/g' \
+                  -e "s/'/\&#39;/g" \
+                  <<< "$line" )" || { echo "FATAL:Error running sed."; };
+        printf "%s\n" "$line";
+    done || {
+        echo "FATAL:Error reading stdin." 1>&2; return 1; };
+};
+generate_wikicode() {
+    # Input:  stdin   validated subpage list
+    # Output: stdout  wikicode
+    local lprev lnext;
+
+    n=0;
+    while read -r line; do
+        #yell "$n:Processing line:$line";  # debug
+        lprev="$lcurr";
+        lcurr="$lnext";
+        lnext="$line";
+        #declare -p lprev lcurr lnext;  # debug
+
+        # Skip first iteration
+        if [[ "$n" -eq 0 ]]; then
+            # yell "$n:DEBUG:Skipping first iteration.";  # debug
+            ((n++));
+            #printf -- "----\n" 1>&2;  # debug
+            continue; fi;
+
+        # Handle first valid input set
+        # yell "$n:DEBUG:Handling first valid input set.";  # debug
+        if [[ "$n" -eq 1 ]]; then
+            printf "[[../%s|Next]], [[../|Up]]\n" \
+                   "$lnext";
+            #printf -- "----\n" 1>&2; # debug
+            ((n++)); continue; fi;
+
+        # Handle middle lines
+        # yell "$n:DEBUG:Handling middle lines.";  # debug
+        printf "[[../%s|Next]], [[../%s|Previous]], [[../|Up]]\n" \
+               "$lnext" "$lprev";
+        ((n++));
+        #printf -- "----\n" 1>&2; # debug
+    done;
+
+    # Handle last line
+    lprev="$lcurr";
+    lcurr="$lnext";
+    lnext="$line";
+    printf "[[../%s|Previous]], [[../|Up]]\n" \
+           "$lprev";
+    ((n++));
+};
+main() {
+    read_input "$@" | validate_subpage_list | generate_wikicode;
+}; # main program
+
+main "$@";