[BK-2020-03.git] / user / bkotslu

#!/bin/bash
# Desc: Utility for backing up and retrieving ots files
# Version: 0.0.2

OTS_FCACHE_DIR="$HOME/.cache/bkotslu/";
MAX_FIND_DEPTH=12;

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
vbm() {
    # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
    # Usage: vbm "DEBUG :verbose message here"
    # Version 0.2.0
    # Input: arg1: string
    #        vars: opVerbose
    # Output: stderr
    # Depends: bash 5.1.16, GNU-coreutils 8.30 (echo, date)

    if [ "$opVerbose" = "true" ]; then
	functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds.
	echo "[$functionTime]:$0:""$*" 1>&2;  # Display argument text.
    fi

    # End function
    return 0; # Function finished.
}; # Displays message if opVerbose true
showUsage() {
    # Desc: Display script usage information
    # Usage: showUsage
    # Version 0.0.2
    # Input: none
    # Output: stdout
    # Depends: GNU-coreutils 8.30 (cat)
    cat <<'EOF'
    USAGE:
        bkotslu [ options ] [FILE...]

    OPTIONS:
        -h, --help
                Display help information.
        --version
                Display script version.
        -v, --verbose
                Display debugging info.
        -i, --input-file
                Define input file path for file to add ots file to.
        -O, --output-dir
                Define output directory path for storing ots backup files.
                  DEFAULT: $HOME/.cache/bkotslu/
        --
                Indicate end of options.

    EXAMPLE:
      Hash foo.txt and lookup matching ots file
        bkotslu -i foo.txt

      Archive ots files from home directory
        bkotslu -I $HOME/

EOF
}; # Display information on how to use this script.
showVersion() {
    # Desc: Displays script version and license information.
    # Usage: showVersion
    # Version: 0.0.2
    # Input: scriptVersion   var containing version string
    # Output: stdout
    # Depends: vbm(), yell, GNU-coreutils 8.30

    # Initialize function
    vbm "DEBUG:showVersion function called."

    cat <<'EOF'
bkotslu 0.0.1
Copyright (C) 2024 Steven Baltakatei Sandoval
License GPLv3: GNU GPL version 3
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

    GNU Coreutils 8.32
    Copyright (C) 2020 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.
EOF
    
    # End function
    vbm "DEBUG:showVersion function ended."
    return 0; # Function finished.
}; # Display script version.
checkDepends() {
    vbm "STATUS:Starting checkDepends()";
    if ! command -v sha256sum 1>/dev/random 2>&1; then
        die "FATAL:sha256sum not available."; fi;
    if ! command -v grep 1>/dev/random 2>&1; then
        die "FATAL:grep not available."; fi;
    if ! command -v find 1>/dev/random 2>&1; then
        die "FATAL:grep not available."; fi;
};
processArgs() {
    # Desc: Processes arguments provided to script.
    # Usage: processArgs "$@"
    # Version: 1.0.0
    # Input: "$@"          (list of arguments provided to the function)
    # Output: Sets following variables used by other functions:
    #   opVerbose            Indicates verbose mode enable status.  (ex: "true", "false")
    #   pathDirOut1          Path to output directory.
    #   pathDirIn1           Path to input directory.
    #   pathFileIn1          Path to input file.
    #   arrayPosArgs         Array of remaining positional argments
    # Depends:
    #   yell()           Displays messages to stderr.
    #   vbm()            Displays messsages to stderr if opVerbose set to "true".
    #   showUsage()      Displays usage information about parent script.
    #   showVersion()    Displays version about parent script.
    #   arrayPosArgs     Global array for storing non-option positional arguments (i.e. arguments following the `--` option).
    # External dependencies: bash (5.1.16), echo
    # Ref./Attrib.:
    #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
    #  [2]: "Handling positional parameters" (2018-05-12). https://wiki.bash-hackers.org/scripting/posparams

    # Initialize function
    vbm "DEBUG:processArgs function called."

    # Perform work
    if [ $# -le 0 ]; then yell "FATAL:No arguments provided."; showUsage; fi;
    while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
	#yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
        #yell "DEBUG:Provided arguments are:""$*"      # Debug stderr message. See [1].
	case "$1" in
	    -h | --help) showUsage; exit 1;; # Display usage.
	    --version) showVersion; exit 1;; # Show version
	    -v | --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
	    -i | --input-file) # Define input file path
		if [ -f "$2" ]; then # If $2 is file that exists, set pathFileIn1 to $2, pop $2.
		    pathFileIn1="$2";
                    vbm "DEBUG:Input file pathFileIn1 set to:${pathFileIn1}";
		    shift;
		else
		    die "FATAL: Specified input file does not exist:$2";
		fi;; 
	    -I | --input-dir) # Define input directory path
		if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirIn1 to $2, pop $2.
		    pathDirIn1="$2";
                    vbm "DEBUG:Input directory pathDirIn1 set to:${pathDirIn1}";
		    shift;		    
		else # Display error if $2 is not a valid dir.
		    die "FATAL:Specified input directory does not exist:$2";
		fi;;
	    -O | --output-dir) # Define output directory path
		if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirOut1 to $2, pop $2
		    pathDirOut1="$2";
                    vbm "DEBUG:Output directory pathDirOut1 set to:${pathDirOut1}";
		    shift;		    
		else
		    die "FATAL:Specified output directory is not valid:$2";
		fi;;
            --) # End of all options. See [2].
                shift;
                for arg in "$@"; do
                    vbm "DEBUG:adding to arrayPosArgs:$arg";
                    arrayPosArgs+=("$arg");
                done;
                break;;
            -*) showUsage; die "FATAL: Unrecognized option.";; # Display usage
	    *) showUsage; die "FATAL: Unrecognized argument.";; # Handle unrecognized options. See [1].
	esac;
	shift;
    done;

    ## Identify ots file cache dir
    if [[ -z "$pathDirOut1" ]]; then
        vbm "STATUS:No output directory for caching OTS files specified.";
        pathDirOut1="$OTS_FCACHE_DIR";
        vbm "STATUS:Assuming OTS files to be cached in:${pathDirOut1}";
    fi;
    ## Create cache dir if necessary
    if [[ ! -d "$pathDirOut1" ]]; then
        vbm "STATUS:Creating OTS file cache directory:${pathDirOut1}";
        must mkdir -p "$pathDirOut1";
    fi;
    
    # End function
    vbm "DEBUG:processArgs function ended.";
    return  0; # Function finished.
}; # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
get_ots_filehash() {
    # Desc: Gets hash of an opentimestamp'd file from ots file
    # Usage: get_ots_filehash FILE
    # Example: get_ots_filehash foo.txt.ots
    # Depends: ots 0.7.0, GNU grep 3.7, GNU Coreutils 8.32
    #          vbm()              verbose output
    #          BK-2020-03  yell()
    # Input:  arg1    OTS file path
    # Output: stdout  sha256 file hash (lowercase)
    local output;
    vbm "DEBUG:Starting get_ots_filehash() on:$1";
    
    if output="$( "$(which ots)" info "$1" | \
            grep -E "^File sha256 hash: " | \
            head -n1 | \
            sed -E -e 's/(^File sha256 hash: )([0-9a-f]+$)/\2/g'; )" && \
            [[ -n "$output" ]]; then
        vbm "STATUS:Read file digest (${output}) via ots from:$1";
        printf "%s" "$output";
        return 0;
    else
        yell "ERROR:Encountered problem getting file hash via ots from:$1";
        return 1;
    fi;
}; # Gets hash of file from ots file
get_ots_oldestblock() {
    # Desc: Gets earliest Bitcoin block number from ots file
    # Usage: get_ots_oldestblock FILE
    # Example: get_ots_oldestblock foo.txt.ots
    # Input: arg1     path  OTS file path
    # Output: stdout  int   Bitcoin block number
    # Depends: OpenTimestamps 0.7.0, GNU grep 3.7, GNU Coreutils 8.32
    #          vbm()
    #          BK-2020-03: yell()
    local output;
    vbm "DEBUG:Starting get_ots_oldestblock() on:$1";
    
    if output="$( "$(which ots)" info "$1" | \
            grep -E "verify BitcoinBlockHeaderAttestation\([0-9]+\)" | \
            sort | head -n1 | \
            sed -E -e 's/(^    verify BitcoinBlockHeaderAttestation)\(([0-9]+)(\))/\2/g'; )" && \
            [[ -n "$output" ]]; then
        vbm "STATUS:Retrieved Bitcoin block (${output}) via ots from:$1";
        printf "%s" "$output";
        return 0;
    else
        yell "ERROR:Encountered problem getting Bitcoin block number via ots from:$1";
        return 1;
    fi;
}; # Gets oldest Bitcoin block from ots file
cache_ots_file() {
    # Desc: Scans and caches an OTS file for storing
    # Input: arg1  input file
    # Output: exit code
    local fin="$1";
    vbm "STATUS:Starting cache_ots_file()";
    
    if [[ ! -f "$fin" ]]; then die "FATAL:OTS file not found:$fin"; fi; 
    if fhash="$(must get_ots_filehash "$fin")" && \
            block="$(must get_ots_oldestblock "$fin")"; then
        fout="${fhash}_${block}.otsu"; # file name out
        pout="${pathDirOut1}/${fout}"; # file path out
        vbm "STATUS:Found OTS file at ${fin} with hash ${fhash} and block ${block}.";
        vbm "STATUS:Saving found OTS file to ${pout}";
        must cp -n "$fin" "$pout";
        return 0;
    else
        yell "ERROR:Problem analyzing file with OpenTimestamps:${fin}";
        return 1;
    fi;
}; # Scans a single OTS file
get_sha256_digest() {
    # Depends: GNU Coreutils 8.32 (sha256sum)
    # Input:  arg1    path  file path
    # Output: stdout  str   sha256 digest (lowercase hexadecimal)
    vbm "DEBUG:Starting get_sha256_digest()";
    sha256sum "$1" | head -n1 | sed -E -e 's/(^[0-9a-f]{64})(.+)/\1/';
};
get_oldest_stored_ots_path() {
    # Desc: Lookup most recent OTS file from storage
    # Input:  pathDirOut1  var  path to OTS storage dir
    #         arg1         str  sha256 digest (lowercase hexadecimal)
    # Output: stdout       path OTS file with matching sha256 digest
    vbm "DEBUG:Starting get_oldest_stored_ots_path()";
    
    digest="$1";
    if output="$( find "$pathDirOut1" -type f -name "${digest}*" | \
            sort | \
            head -n1 )" && \
            [[ -n "$output" ]]; then
        output="$(readlink -f "$output")";
        vbm "STATUS:Found matching OTS file with digest ${digest} at:$output";
        printf "%s" "$output";
        return 0;
    else
        yell "ERROR:Could not find matching OTS file with digest ${digest} in ${pathDirOut1}";
        return 1;
    fi;
};
main() {
    checkDepends;
    processArgs "$@";
    vbm "DEBUG:Starting rest of main()";

    # Scan provided dir for OTS files to cache.
    if [[ -n "$pathDirIn1" ]]; then
        while read -r line; do
            line="$(readlink -f "$line")";
            cache_ots_file "$line";
        done < <(find "$pathDirIn1" -maxdepth "$MAX_FIND_DEPTH" -type f -name "*.ots");
    fi;

    # Lookup OTS file from archive for provided file.
    if [[ -n "$pathFileIn1" ]]; then
        # Check for and store any OTS file attached to provided file
        if [[ -f "${pathFileIn1}.ots" ]]; then
            vbm "STATUS:OTS file accompanying provided file found:${pathFileIn1}.ots";
            cache_ots_file "${pathFileIn1}.ots" && vbm "STATUS:Stored provided file's OTS file.";
        fi;
        
        # Get file hash
        fhash="$(get_sha256_digest "$pathFileIn1"; )";
        if path_stored_ots="$(get_oldest_stored_ots_path "$fhash"; )"; then
            vbm "STATUS:Stored OTS found with matching hash.";
            blk_stored="$(get_ots_oldestblock "$path_stored_ots"; )";
            vbm "STATUS:Stored OTS file has block number ${blk_stored}.";
            if [[ -f "${pathFileIn1}.ots" ]]; then
                vbm "STATUS:An OTS file is next to provided file.";
                blk_provid="$(get_ots_oldestblock "${pathFileIn1}.ots"; )";
                vbm "STATUS:Provided file's OTS file has block number ${blk_provid}";
                if [[ "$blk_stored" -lt "$blk_provid" ]]; then
                    vbm "STATUS:Older timestamp in OTS store found. Replacing ${pathFileIn1} (block ${blk_provid}) with ${path_stored_ots} (block ${blk_stored}).";
                    #must mv "$pathFileIn1" "${pathFileIn1}.baku";
                    #must cp "$path_stored_ots" "$pathFileIn1";
                else
                    yell "STATUS:Stored OTS file (block ${blk_stored}) is not older than provided file's OTS file (block ${blk_provid}). No action taken for:${pathFileIn1}";
                fi;
            else
                vbm "STATUS:Stored OTS file found with digest matching provided file. Copying ${path_stored_ots} to ${pathFileIn1}.ots";
                must cp "$path_stored_ots" "${pathFileIn1}.ots";
            fi;
        else
            vbm "STATUS:No stored OTS found. No action taken for:${pathFileIn1}";
        fi;
    fi;

}; # main program

main "$@";
Commit	Line	Data
aa8be4bf SBS	1	#!/bin/bash
aa8be4bf SBS	2	# Desc: Utility for backing up and retrieving ots files
df7774c1	3	# Version: 0.0.2
aa8be4bf SBS	4
	5	OTS_FCACHE_DIR="$HOME/.cache/bkotslu/";
	6	MAX_FIND_DEPTH=12;
	7
	8	yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
	9	die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
	10	must() { "$@" \|\| die "cannot $*"; } # runs args as command, reports args if command fails
	11	vbm() {
	12	# Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
	13	# Usage: vbm "DEBUG :verbose message here"
	14	# Version 0.2.0
	15	# Input: arg1: string
	16	# vars: opVerbose
	17	# Output: stderr
	18	# Depends: bash 5.1.16, GNU-coreutils 8.30 (echo, date)
	19
	20	if [ "$opVerbose" = "true" ]; then
	21	functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds.
	22	echo "[$functionTime]:$0:""$*" 1>&2; # Display argument text.
	23	fi
	24
	25	# End function
	26	return 0; # Function finished.
	27	}; # Displays message if opVerbose true
	28	showUsage() {
	29	# Desc: Display script usage information
	30	# Usage: showUsage
	31	# Version 0.0.2
	32	# Input: none
	33	# Output: stdout
	34	# Depends: GNU-coreutils 8.30 (cat)
	35	cat <<'EOF'
	36	USAGE:
	37	bkotslu [ options ] [FILE...]
	38
	39	OPTIONS:
	40	-h, --help
	41	Display help information.
	42	--version
	43	Display script version.
	44	-v, --verbose
	45	Display debugging info.
	46	-i, --input-file
	47	Define input file path for file to add ots file to.
	48	-O, --output-dir
	49	Define output directory path for storing ots backup files.
	50	DEFAULT: $HOME/.cache/bkotslu/
	51	--
	52	Indicate end of options.
	53
	54	EXAMPLE:
	55	Hash foo.txt and lookup matching ots file
	56	bkotslu -i foo.txt
	57
	58	Archive ots files from home directory
	59	bkotslu -I $HOME/
	60
	61	EOF
	62	}; # Display information on how to use this script.
	63	showVersion() {
	64	# Desc: Displays script version and license information.
	65	# Usage: showVersion
	66	# Version: 0.0.2
	67	# Input: scriptVersion var containing version string
68	# Output: stdout
69	# Depends: vbm(), yell, GNU-coreutils 8.30
70
71	# Initialize function
72	vbm "DEBUG:showVersion function called."
73
74	cat <<'EOF'
75	bkotslu 0.0.1
76	Copyright (C) 2024 Steven Baltakatei Sandoval
77	License GPLv3: GNU GPL version 3
78	This is free software; you are free to change and redistribute it.
79	There is NO WARRANTY, to the extent permitted by law.
80
81	GNU Coreutils 8.32
82	Copyright (C) 2020 Free Software Foundation, Inc.
83	License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
84	This is free software: you are free to change and redistribute it.
85	There is NO WARRANTY, to the extent permitted by law.
86	EOF
87
88	# End function
89	vbm "DEBUG:showVersion function ended."
90	return 0; # Function finished.
91	}; # Display script version.
df7774c1 SBS	92	checkDepends() {
	93	vbm "STATUS:Starting checkDepends()";
	94	if ! command -v sha256sum 1>/dev/random 2>&1; then
	95	die "FATAL:sha256sum not available."; fi;
	96	if ! command -v grep 1>/dev/random 2>&1; then
	97	die "FATAL:grep not available."; fi;
	98	if ! command -v find 1>/dev/random 2>&1; then
	99	die "FATAL:grep not available."; fi;
	100	};
aa8be4bf SBS	101	processArgs() {
	102	# Desc: Processes arguments provided to script.
	103	# Usage: processArgs "$@"
	104	# Version: 1.0.0
	105	# Input: "$@" (list of arguments provided to the function)
	106	# Output: Sets following variables used by other functions:
	107	# opVerbose Indicates verbose mode enable status. (ex: "true", "false")
	108	# pathDirOut1 Path to output directory.
	109	# pathDirIn1 Path to input directory.
	110	# pathFileIn1 Path to input file.
	111	# arrayPosArgs Array of remaining positional argments
	112	# Depends:
	113	# yell() Displays messages to stderr.
	114	# vbm() Displays messsages to stderr if opVerbose set to "true".
	115	# showUsage() Displays usage information about parent script.
	116	# showVersion() Displays version about parent script.
	117	# arrayPosArgs Global array for storing non-option positional arguments (i.e. arguments following the `--` option).
	118	# External dependencies: bash (5.1.16), echo
	119	# Ref./Attrib.:
	120	# [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
	121	# [2]: "Handling positional parameters" (2018-05-12). https://wiki.bash-hackers.org/scripting/posparams
	122
	123	# Initialize function
	124	vbm "DEBUG:processArgs function called."
	125
	126	# Perform work
	127	if [ $# -le 0 ]; then yell "FATAL:No arguments provided."; showUsage; fi;
	128	while [ ! $# -eq 0 ]; do # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
	129	#yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
	130	#yell "DEBUG:Provided arguments are:""$*" # Debug stderr message. See [1].
	131	case "$1" in
	132	-h \| --help) showUsage; exit 1;; # Display usage.
	133	--version) showVersion; exit 1;; # Show version
	134	-v \| --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
	135	-i \| --input-file) # Define input file path
	136	if [ -f "$2" ]; then # If $2 is file that exists, set pathFileIn1 to $2, pop $2.
	137	pathFileIn1="$2";
	138	vbm "DEBUG:Input file pathFileIn1 set to:${pathFileIn1}";
	139	shift;
	140	else
	141	die "FATAL: Specified input file does not exist:$2";
	142	fi;;
	143	-I \| --input-dir) # Define input directory path
	144	if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirIn1 to $2, pop $2.
	145	pathDirIn1="$2";
	146	vbm "DEBUG:Input directory pathDirIn1 set to:${pathDirIn1}";
	147	shift;
	148	else # Display error if $2 is not a valid dir.
	149	die "FATAL:Specified input directory does not exist:$2";
	150	fi;;
	151	-O \| --output-dir) # Define output directory path
	152	if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirOut1 to $2, pop $2
	153	pathDirOut1="$2";
	154	vbm "DEBUG:Output directory pathDirOut1 set to:${pathDirOut1}";
	155	shift;
	156	else
	157	die "FATAL:Specified output directory is not valid:$2";
	158	fi;;
	159	--) # End of all options. See [2].
	160	shift;
	161	for arg in "$@"; do
	162	vbm "DEBUG:adding to arrayPosArgs:$arg";
	163	arrayPosArgs+=("$arg");
	164	done;
165	break;;
166	-*) showUsage; die "FATAL: Unrecognized option.";; # Display usage
167	*) showUsage; die "FATAL: Unrecognized argument.";; # Handle unrecognized options. See [1].
168	esac;
169	shift;
170	done;
171
172	## Identify ots file cache dir
173	if [[ -z "$pathDirOut1" ]]; then
174	vbm "STATUS:No output directory for caching OTS files specified.";
175	pathDirOut1="$OTS_FCACHE_DIR";
176	vbm "STATUS:Assuming OTS files to be cached in:${pathDirOut1}";
177	fi;
178	## Create cache dir if necessary
179	if [[ ! -d "$pathDirOut1" ]]; then
180	vbm "STATUS:Creating OTS file cache directory:${pathDirOut1}";
181	must mkdir -p "$pathDirOut1";
182	fi;
183
184	# End function
185	vbm "DEBUG:processArgs function ended.";
186	return 0; # Function finished.
187	}; # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
188	get_ots_filehash() {
189	# Desc: Gets hash of an opentimestamp'd file from ots file
190	# Usage: get_ots_filehash FILE
191	# Example: get_ots_filehash foo.txt.ots
192	# Depends: ots 0.7.0, GNU grep 3.7, GNU Coreutils 8.32
193	# vbm() verbose output
194	# BK-2020-03 yell()
195	# Input: arg1 OTS file path
196	# Output: stdout sha256 file hash (lowercase)
197	local output;
aa8be4bf	198	vbm "DEBUG:Starting get_ots_filehash() on:$1";
df7774c1	199
aa8be4bf SBS	200	if output="$( "$(which ots)" info "$1" \| \
	201	grep -E "^File sha256 hash: " \| \
	202	head -n1 \| \
	203	sed -E -e 's/(^File sha256 hash: )([0-9a-f]+$)/\2/g'; )" && \
	204	[[ -n "$output" ]]; then
df7774c1	205	vbm "STATUS:Read file digest (${output}) via ots from:$1";
aa8be4bf SBS	206	printf "%s" "$output";
	207	return 0;
	208	else
	209	yell "ERROR:Encountered problem getting file hash via ots from:$1";
	210	return 1;
	211	fi;
	212	}; # Gets hash of file from ots file
	213	get_ots_oldestblock() {
	214	# Desc: Gets earliest Bitcoin block number from ots file
	215	# Usage: get_ots_oldestblock FILE
	216	# Example: get_ots_oldestblock foo.txt.ots
	217	# Input: arg1 path OTS file path
	218	# Output: stdout int Bitcoin block number
	219	# Depends: OpenTimestamps 0.7.0, GNU grep 3.7, GNU Coreutils 8.32
	220	# vbm()
	221	# BK-2020-03: yell()
	222	local output;
df7774c1 SBS	223	vbm "DEBUG:Starting get_ots_oldestblock() on:$1";
df7774c1 SBS	224
aa8be4bf SBS	225	if output="$( "$(which ots)" info "$1" \| \
	226	grep -E "verify BitcoinBlockHeaderAttestation\([0-9]+\)" \| \
	227	sort \| head -n1 \| \
	228	sed -E -e 's/(^ verify BitcoinBlockHeaderAttestation)\(([0-9]+)(\))/\2/g'; )" && \
	229	[[ -n "$output" ]]; then
df7774c1	230	vbm "STATUS:Retrieved Bitcoin block (${output}) via ots from:$1";
aa8be4bf SBS	231	printf "%s" "$output";
	232	return 0;
	233	else
	234	yell "ERROR:Encountered problem getting Bitcoin block number via ots from:$1";
	235	return 1;
	236	fi;
	237	}; # Gets oldest Bitcoin block from ots file
	238	cache_ots_file() {
	239	# Desc: Scans and caches an OTS file for storing
df7774c1 SBS	240	# Input: arg1 input file
	241	# Output: exit code
	242	local fin="$1";
	243	vbm "STATUS:Starting cache_ots_file()";
	244
	245	if [[ ! -f "$fin" ]]; then die "FATAL:OTS file not found:$fin"; fi;
	246	if fhash="$(must get_ots_filehash "$fin")" && \
	247	block="$(must get_ots_oldestblock "$fin")"; then
aa8be4bf SBS	248	fout="${fhash}_${block}.otsu"; # file name out
aa8be4bf SBS	249	pout="${pathDirOut1}/${fout}"; # file path out
df7774c1 SBS	250	vbm "STATUS:Found OTS file at ${fin} with hash ${fhash} and block ${block}.";
	251	vbm "STATUS:Saving found OTS file to ${pout}";
	252	must cp -n "$fin" "$pout";
	253	return 0;
aa8be4bf	254	else
df7774c1 SBS	255	yell "ERROR:Problem analyzing file with OpenTimestamps:${fin}";
df7774c1 SBS	256	return 1;
aa8be4bf SBS	257	fi;
aa8be4bf SBS	258	}; # Scans a single OTS file
df7774c1 SBS	259	get_sha256_digest() {
	260	# Depends: GNU Coreutils 8.32 (sha256sum)
	261	# Input: arg1 path file path
	262	# Output: stdout str sha256 digest (lowercase hexadecimal)
	263	vbm "DEBUG:Starting get_sha256_digest()";
	264	sha256sum "$1" \| head -n1 \| sed -E -e 's/(^[0-9a-f]{64})(.+)/\1/';
	265	};
	266	get_oldest_stored_ots_path() {
	267	# Desc: Lookup most recent OTS file from storage
	268	# Input: pathDirOut1 var path to OTS storage dir
	269	# arg1 str sha256 digest (lowercase hexadecimal)
	270	# Output: stdout path OTS file with matching sha256 digest
	271	vbm "DEBUG:Starting get_oldest_stored_ots_path()";
	272
	273	digest="$1";
	274	if output="$( find "$pathDirOut1" -type f -name "${digest}*" \| \
	275	sort \| \
	276	head -n1 )" && \
	277	[[ -n "$output" ]]; then
	278	output="$(readlink -f "$output")";
	279	vbm "STATUS:Found matching OTS file with digest ${digest} at:$output";
	280	printf "%s" "$output";
	281	return 0;
	282	else
	283	yell "ERROR:Could not find matching OTS file with digest ${digest} in ${pathDirOut1}";
	284	return 1;
	285	fi;
	286	};
aa8be4bf	287	main() {
df7774c1	288	checkDepends;
aa8be4bf	289	processArgs "$@";
df7774c1	290	vbm "DEBUG:Starting rest of main()";
aa8be4bf SBS	291
	292	# Scan provided dir for OTS files to cache.
	293	if [[ -n "$pathDirIn1" ]]; then
	294	while read -r line; do
	295	line="$(readlink -f "$line")";
df7774c1	296	cache_ots_file "$line";
aa8be4bf SBS	297	done < <(find "$pathDirIn1" -maxdepth "$MAX_FIND_DEPTH" -type f -name "*.ots");
	298	fi;
	299
	300	# Lookup OTS file from archive for provided file.
	301	if [[ -n "$pathFileIn1" ]]; then
df7774c1 SBS	302	# Check for and store any OTS file attached to provided file
	303	if [[ -f "${pathFileIn1}.ots" ]]; then
	304	vbm "STATUS:OTS file accompanying provided file found:${pathFileIn1}.ots";
	305	cache_ots_file "${pathFileIn1}.ots" && vbm "STATUS:Stored provided file's OTS file.";
	306	fi;
	307
	308	# Get file hash
	309	fhash="$(get_sha256_digest "$pathFileIn1"; )";
	310	if path_stored_ots="$(get_oldest_stored_ots_path "$fhash"; )"; then
	311	vbm "STATUS:Stored OTS found with matching hash.";
	312	blk_stored="$(get_ots_oldestblock "$path_stored_ots"; )";
	313	vbm "STATUS:Stored OTS file has block number ${blk_stored}.";
	314	if [[ -f "${pathFileIn1}.ots" ]]; then
	315	vbm "STATUS:An OTS file is next to provided file.";
	316	blk_provid="$(get_ots_oldestblock "${pathFileIn1}.ots"; )";
	317	vbm "STATUS:Provided file's OTS file has block number ${blk_provid}";
	318	if [[ "$blk_stored" -lt "$blk_provid" ]]; then
	319	vbm "STATUS:Older timestamp in OTS store found. Replacing ${pathFileIn1} (block ${blk_provid}) with ${path_stored_ots} (block ${blk_stored}).";
	320	#must mv "$pathFileIn1" "${pathFileIn1}.baku";
	321	#must cp "$path_stored_ots" "$pathFileIn1";
	322	else
	323	yell "STATUS:Stored OTS file (block ${blk_stored}) is not older than provided file's OTS file (block ${blk_provid}). No action taken for:${pathFileIn1}";
	324	fi;
	325	else
	326	vbm "STATUS:Stored OTS file found with digest matching provided file. Copying ${path_stored_ots} to ${pathFileIn1}.ots";
	327	must cp "$path_stored_ots" "${pathFileIn1}.ots";
	328	fi;
	329	else
	330	vbm "STATUS:No stored OTS found. No action taken for:${pathFileIn1}";
	331	fi;
aa8be4bf	332	fi;
aa8be4bf SBS	333
	334	}; # main program
	335
	336	main "$@";