unitproc/bklu

   1 #!/bin/bash
   2
   3 # Date: 2020-05-04T18:50Z
   4 # Author: Steven Baltakatei Sandoval
   5 # Description: Script to lookup file hash from existing hash list.
   6 # Note: Use hide-show-block function to aid readability. (ex: https://www.emacswiki.org/emacs/HideShow ).
   7
   8 #== Variable Initialization ==
   9
  10 #== Global constants ==
  11 SCRIPT_TTL=10                   # Limit script life to this in seconds.
  12 PATH="/usr/local/bin/:$PATH"    # Add user binary executable directory to PATH.
  13 PATH="/opt/bktei:$PATH"         # Add 'optional' executable directory to PATH.
  14 SCRIPT_HOSTNAME=$(hostname)     # Save hostname of system running this script.
  15 SCRIPT_VERSION="bktemplate.sh 0.0.0" # Define version of script. Used by function 'showVersion'.
  16 SCRIPT_TIME_SHORT="$(date +%Y%m%dT%H%M%S%z)" # Save current date & time in ISO-8601 format (YYYYmmddTHHMMSS+zzzz).
  17 SCRIPT_DATE_SHORT="$(date +%Y%m%d)"          # Save current date in ISO-8601 format.
  18
  19 #== Function Definitions ==
  20 echoerr() {
  21     # Usage: echo [ arguments ]
  22     # Description: Prints provided arguments to stderr.
  23     # Input: unspecified
  24     # Output: stderr
  25     # Script function dependencies: none
  26     # External function dependencies: echo
  27     # Last modified: 2020-04-11T21:16Z
  28     # Last modified by: Steven Baltakatei Sandoval
  29     # License: GPLv3+
  30     # Ref./Attrib:
  31     #  [1]: # Roth, James (2010-06-07). ["How to print text to stderr instead of stdout"](https://stackoverflow.com/a/2990533). Licensed CC BY-SA 4.0.
  32
  33     echo "$@" 1>&2; # Define stderr echo function. See [1].
  34     return 0; # Function finished.
  35 } # Define stderr message function.
  36 vbm() {
  37     # Usage: vbm "DEBUG:verbose message here"
  38     # Description: Prints verbose message ("vbm") to stderr if OPTION_VERBOSE is set to "true".
  39     # Input:
  40     #   - OPTION_VERBOSE  variable set by processArguments function. (ex: "true", "false")
  41     #   - "$@"            positional arguments fed to this function.
  42     # Output: stderr
  43     # Script function dependencies: echoerr
  44     # External function dependencies: echo
  45     # Last modified: 2020-04-11T23:57Z
  46     # Last modified by: Steven Baltakatei Sandoval
  47     # License: GPLv3+
  48     # Ref./Attrib:
  49
  50     if [ "$OPTION_VERBOSE" == "true" ]; then
  51         FUNCTION_TIME=$(date --iso-8601=ns); # Save current time in nano seconds.
  52         echoerr "[$FUNCTION_TIME] ""$@"; # Display argument text.
  53     fi
  54
  55     # End function
  56     return 0; # Function finished.
  57 } # Verbose message display function.
  58 showUsage() {
  59     # Usage: showUsage
  60     # Description: Displays script usage information.
  61     # Input: none
  62     # Output: stderr
  63     # Script function dependencies: echoerr
  64     # External dependencies: bash (5.0.3), echo
  65     # Last modified: 2020-05-04T16:58Z
  66     # Last modified by: Steven Baltakatei Sandoval
  67     # License: GPLv3+
  68     # Ref./Attrib.:
  69
  70     echoerr "USAGE:"
  71     echoerr "    bklu [OPTIONS] [FILE]"
  72     echoerr
  73     echoerr "    [FILE] hash is compared against file contents of directory"
  74     echoerr "      specified by --input-dir option or environment variable"
  75     echoerr "      BK_FILEHASHLIST_DIR ."
  76     echoerr
  77     echoerr "OPTIONS:"
  78     echoerr "    --digest-algo [ digest name ]"
  79     echoerr "            Specify digest command name. Value should be GNU"
  80     echoerr "            coreutils commands such as: sha256sum, md5sum, b2sum."
  81     echoerr "            Default value is: b2sum"
  82     echoerr
  83     echoerr "    -h, --help"
  84     echoerr "            Display help information."
  85     echoerr
  86     echoerr "    --version"
  87     echoerr "            Display script version."
  88     echoerr
  89     echoerr "    -v, --verbose"
  90     echoerr "            Display debugging info."
  91     echoerr
  92     echoerr "    -o, --output-file [ file ]"
  93     echoerr "            Specify output file."
  94     echoerr
  95     echoerr "    -i, --input-file [ file ]"
  96     echoerr "            Specify input file."
  97     echoerr
  98     echoerr "    -o, --output-dir [ directory ]"
  99     echoerr "            Specify output directory."
 100     echoerr
 101     echoerr "    -i, --input-dir [ directory ]"
 102     echoerr "            Specify input directory."
 103     echoerr
 104
 105
 106     # End function
 107     return 0; # Function finished.
 108 } # Display information on how to use this script.
 109 showVersion() {
 110     # Usage: showVersion
 111     # Descriptoin: Displays script version and license information.
 112     # Input: unspecified
 113     # Output: stderr
 114     # Script function dependencies: echoerr
 115     # External function dependencies: echo
 116     # Last modified: 2020-04-11T23:57Z
 117     # Last modified by: Steven Baltakatei Sandoval
 118     # License: GPLv3+
 119     # Ref./Attrib:
 120
 121     # Initialize function
 122     vbm "DEBUG:showVersion function called."
 123
 124     # Perform work
 125     OUTPUT="$SCRIPT_VERSION"
 126
 127     # Display results
 128     echoerr "$OUTPUT";
 129
 130     # End function
 131     vbm "DEBUG:showVersion function ended."
 132     return 0; # Function finished.
 133 } # Display script version.
 134 processArguments() {
 135     # Usage: processArguments "$@"
 136     # Description: Processes provided arguments in order to set script option variables useful for
 137     #   changing how other functions behave. For example, it may:
 138     #   1. Activate verbose mode
 139     # Input: "$@"          (list of arguments provided to the function)
 140     # Output: Sets following variables used by other functions:
 141     #   OPTION_VERBOSE     Indicates verbose mode enable status.  (ex: "true", "false")
 142     #   DIROUT1            Path to output directory.
 143     #   FILEOUT1           Path to output file.
 144     #   DIRIN1             Path to input directory.
 145     #   FILEIN1            Path to input file.
 146     #   OPTION_FILEOUT1_OVERWRITE Indicates whether file FILEOUT1 should be overwritten (ex: "true", "false')
 147     #   DIGEST_ALGO        Name of digest command (unverified).
 148     # Script function dependencies:
 149     #   - echoerr          Displays messages to stderr.
 150     #   - vbm              Displays messsages to stderr if OPTION_VERBOSE set to "true".
 151     # External dependencies: bash (5.0.3), echo
 152     # Last modified: 2020-05-04T18:13Z
 153     # Last modified by: Steven Baltakatei Sandoval
 154     # License: GPLv3+
 155     # Ref./Attrib.:
 156     #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
 157
 158     # Initialize function
 159     #vbm "DEBUG:processArguments function called."
 160
 161     # Perform work
 162     while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
 163         #1>&2 echo "DEBUG:Starting processArguments while loop." # Debug stderr message. See [1].
 164         #1>&2 echo "DEBUG:Provided arguments are:""$@" # Debug stderr message. See [1].
 165         case "$1" in
 166             -h | --help) showUsage; exit 1;; # Display usage.
 167             --version) showVersion; exit 1;; # Show version
 168             -v | --verbose) OPTION_VERBOSE="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
 169             -i | --input-file) # Define input file path
 170                 if [ -f "$2" ]; then # If $2 is file that exists, set FILEIN1 to $2, pop $2.
 171                     FILEIN1="$2";
 172                     shift;
 173                     vbm "DEBUG:Input file FILEIN1 set to:""$2";
 174                 else
 175                     echoerr "ERROR: Specified input file does not exist:""$2";
 176                     echoerr "Exiting.";
 177                     exit 1;
 178                 fi ;;
 179             -I | --input-dir) # Define input directory path.
 180                 if [ -d "$2" ]; then # If $2 is dir that exists, set DIRIN1 to $2, pop $2.
 181                     DIRIN1="$2";
 182                     shift;
 183                     vbm "DEBUG:Input directory DIRIN1 set to:""$2";
 184                 else # Display error if $2 is not a valid dir.
 185                     echoerr "ERROR:Specified input directory does not exist:""$2";
 186                     echoerr "Exiting.";
 187                     exit 1;
 188                 fi ;;
 189             -o | --output-file) # Define output file path
 190                 if [ -f "$2" ]; then # If $2 is file that exists, prompt user to continue to overwrite, set FILEOUT1 to $2, pop $2.
 191                     echoerr "Specified output file $2 already exists. Overwrite? (y/n):"
 192                     read m; case $m in
 193                                 y | Y | yes) OPTION_FILEOUT1_OVERWRITE="true";;
 194                                 n | N | no) OPTION_FILEOUT1_OVERWRITE="false";;
 195                                 *) echoerr "Invalid selection. Exiting."; exit 1;;
 196                             esac
 197                     if [ "$OPTION_FILEOUT1_OVERWRITE" == "true" ]; then
 198                         FILEOUT1="$2";
 199                         shift;
 200                         vbm "DEBUG:Output file FILEOUT1 set to:""$2";
 201                     else
 202                         echoerr "ERORR:Exiting in order to not overwrite output file:""$FILEOUT1";
 203                         exit 1;
 204                     fi
 205                 else
 206                     FILEOUT1="$2";
 207                     shift;
 208                     vbm "DEBUG:Output file FILEOUT1 set to:""$2";
 209                 fi ;;
 210             -O | --output-dir) # Define output directory path
 211                 if [ -d "$2" ]; then # If $2 is dir that exists, set DIROUT1 to $2, pop $2
 212                     DIROUT1="$2";
 213                     shift;
 214                     vbm "DEBUG:Output directory DIROUT1 set to:""$2";
 215                 else
 216                     echoerr "ERROR:Specified output directory is not valid:""$2";
 217                     echoerr "Exiting.";
 218                     exit 1;
 219                 fi ;;
 220             --digest-algo) # Define file digest algorithm command name.
 221                 if ! [ -z "$2" ]; then # If $2 is non-zero, set DIGEST_ALGO to $2, pop $2
 222                     DIGEST_ALGO="$2";
 223                     shift;
 224                     vbm "DEBUG:DIGEST_ALGO set to:""$DIGEST_ALGO";
 225                 else
 226                     echoerr "ERROR:Cannot set DIGEST_ALGO because no string specified."; echoerr "Exiting."; exit 1;
 227                 fi ;;
 228             *) if [ -f "$1" ] && ! [ -v FILEIN1 ]; then # If $1 is file and FILEIN1 not set, then set FILEIN1 to $1, pop $1.
 229                    FILEIN1="$1";
 230                    shift;
 231                    vbm "DEBUG:FILEIN1 set to:""$FILEIN1";
 232                else # Handle non-option (ex: [FILE] )
 233                    echoerr "ERROR: Unrecognized non-option argument."; echoerr "Exiting."; exit 1;
 234                fi ;;
 235         esac
 236         shift;
 237     done
 238
 239     # End function
 240     vbm "DEBUG:processArguments function ended."
 241     return  0; # Function finished.
 242 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
 243 checkExecutables() {
 244     # Usage: checkExecutables [ command1 ] [ command2 ] [...] [ commandN ]
 245     # Description: Checks that provided commands exist. If one or more do not exist, then display missing commands and exit with error.
 246     # Input:
 247     #   - command names (arguments)
 248     # Output: commands that don't exist (stderr)
 249     # Script function dependencies:
 250     #   - echoerr          for displaying errors via stderr
 251     #   - processArguments for setting OPTION_VERBOSE
 252     #   - vbm              for displaying verbose messages if OPTION_VERBOSE is "true"
 253     # External dependencies: bash (5.0.3), command
 254     # Last modified: 2020-05-04T17:12Z
 255     # Last modified by: Steven Baltakatei Sandoval
 256     # License: GPLv3+
 257     # Ref./Attrib.:
 258     #  [1]: SiegeX (2010-12-12). ["Difference between return and exit in Bash functions."](https://stackoverflow.com/a/4419971). Licensed CC BY-SA 4.0.
 259     #  [2]: Darryl Hein (2009-12-23). ["Add a new element to an array without specifying the index in Bash"](https://stackoverflow.com/a/1951523). Licensed CC BY-SA 4.0.
 260     #  [3]: kojiro (2012-10-03). ["Convert command line arguments into an array in Bash"](https://stackoverflow.com/a/12711853)
 261     #  [4]: niieani (2016-01-12). ["How to copy an array in Bash?"](https://stackoverflow.com/a/34733375/10850071). Licensed CC BY-SA 4.0.
 262
 263     # Initialize function
 264     vbm "DEBUG:checkExecutables function called."
 265     declare -a candidateCommandsNames # Initialize array for storing positional arguments provided to this function.
 266     candidateCommandsNames=("$@") # Save positional arguments to variable as string. See [3].
 267     vbm "DEBUG:candidateCommandsNames:""$@"
 268     vbm "DEBUG:candidateCommandsNames[0]:""${candidateCommandsNames[0]}"
 269     vbm "DEBUG:candidateCommandsNames[1]:""${candidateCommandsNames[1]}"
 270     vbm "DEBUG:candidateCommandsNames[2]:""${candidateCommandsNames[2]}"
 271     declare -a outputInvalidCommandsArray # Initialize arary for storing names of invalid commands.
 272     declare -a outputValidCommandsArray # Initialize array for storing names of valid commands.
 273
 274     # Perform work
 275     for candidateCommandName in "${candidateCommandsNames[@]}"; do  # Search through all space-delimited text for valid commands.
 276         if command -v "$candidateCommandName" 1>/dev/null 2>/dev/null; then # Check if a command is valid or not.
 277             outputValidCommandsArray+=("$candidateCommandName") ; # See [2].
 278             vbm "DEBUG:Adding $candidateCommandName to outputValidCommandsArray."
 279         else
 280             outputInvalidCommandsArray+=("$candidateCommandName") ; # See [2].
 281             vbm "DEBUG:Adding $candidateCommandName to outputInvalidCommandsArray."
 282         fi
 283     done
 284
 285     # Output results
 286     if [ ${#outputInvalidCommandsArray[@]} -gt 0 ]; then # if number of elements in outputInvalidCommandsArray greater than 0, then display offending commands and exit 1.
 287         echoerr "ERROR: Invalid commands found:""${outputInvalidCommandsArray[@]}"; # display invalid commands as error
 288         exit 1; # See [1].
 289     elif [ ${#outputInvalidCommandsArray[@]} -eq 0 ]; then # if number of elements in outputInvalidCommandsArray equals zero, then return 0.
 290         vbm "DEBUG: Valid commands are:""${outputValidCommandsArray[@]}"; # display valid commands if verbose mode enabled
 291         return 0; # See [1].
 292     else
 293         echoerr "ERROR: Check outputInvalidCommandsArray.";
 294     fi
 295
 296     # End function
 297     vbm "DEBUG:checkExecutables function ended."
 298     return 0; # Function finished.
 299 } # Check that certain executables exist.
 300 updateTimeConstants() {
 301     # Usage: updateTimeConstants
 302     # Description: Updates time-related variables for use by other scripts.
 303     # Input: (none)
 304     # Output: Sets following variables:
 305     #   TIME_CURRENT       Current time in long ISO-8601 format.  (ex: YYYY-mm-ddTHH:MM:SS+ZZZZ)
 306     #   TIME_CURRENT_SHORT Current time in short ISO-8601 format. (ex: YYYYmmddTHHMMSS+ZZZZ)
 307     #   DATE_CURRENT       Current date in ISO-8601 format.       (ex: YYYY-mm-dd)
 308     #   DATE_CURRENT_SHORT Current date in short ISO-8601 format. (ex: YYYYmmdd)
 309     #   DATE_TOMORROW      Tomorrow's date in ISO-8601 format.    (ex: YYYY-mm-dd)
 310     #   TIME_NEXT_MIDNIGHT Time of tomorrow's midnight in long    (ex: YYYY-mm-ddTHH:MM:SS+ZZZZ)
 311     #                       ISO-861 format.
 312     #   SEC_TIL_MIDNIGHT   Seconds until next midnight.
 313     # Script function dependencies:
 314     #   - echoerr          for displaying errors via stderr
 315     #   - processArguments for setting OPTION_VERBOSE
 316     #   - vbm              for displaying verbose messages if OPTION_VERBOSE is "true"
 317     # External dependencies: bash (5.0.3), date, echo
 318     # Last modified: 2020-04-11T23:59Z
 319     # Last modified by: Steven Baltakatei Sandoval
 320     # License: GPLv3+
 321     # Ref./Attrib.:
 322
 323     # Initialize function
 324     vbm "DEBUG:updateTimeConstants function called."
 325
 326     # Perform work
 327     TIME_CURRENT="$(date --iso-8601=seconds)" ;
 328     TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)"
 329     DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ;
 330     DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ;
 331     DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ;
 332     TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ;
 333     SECONDS_UNTIL_NEXT_MIDNIGHT="$((  $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT")  ))" ;
 334
 335     # End function
 336     vbm "DEBUG:updateTimeConstants function ended."
 337     return 0; # Function finished.
 338 } # Update time constants
 339 getGnucuDigest() {
 340     # Usage: getGnucuDigest [algo] [file]
 341     # Description: Calculates cryptographic digest using specified GnuCoreutils command.
 342     # Input:
 343     #   $1: [algo]     (ex: sha256sum, sha512sum, b2sum, md5sum)
 344     #   $2: [file]
 345     # Output: stdout
 346     # Script function dependencies:
 347     #   - echoerr          for displaying errors via stderr
 348     #   - processArguments for setting OPTION_VERBOSE
 349     #   - vbm              for displaying verbose messages if OPTION_VERBOSE is "true"
 350     #   - checkExecutables for checking that digest algo commands exist
 351     # External dependencies: bash (5.0.3), echo, awk
 352     # Last modified: 2020-05-04T18:51Z
 353     # Last modified by: Steven Baltakatei Sandoval
 354     # License: GPLv3+
 355     # Ref./Attrib.:
 356     #  [1]: gnu.org (2000-11). [GNU Coreutils](https://www.gnu.org/software/coreutils/manual/coreutils.html). Licensed FDL v1.3+.
 357     #  [2]: linuxize.com (2019-07-19). [How to Check if a String Contains a Substring in Bash](https://linuxize.com/post/how-to-check-if-string-contains-substring-in-bash/).
 358
 359     # Initialize function
 360     vbm "DEBUG:getGnucuDigest function called."
 361     DIGEST_ALGO=$1 # Define candidate digest algorithm
 362     TARGET_FILE=$2 # Define target file to be digested
 363     GNUCU_DIGESTS="b2sum md5sum sha1sum sha224sum sha256sum sha384sum sha512sum" # Define space-delimited string with GNU Coreutils digest algorithms. See [1].
 364     vbm "DEBUG:DIGEST_ALGO set to:""$DIGEST_ALGO"
 365     vbm "TARGET_FILE set to:""$TARGET_FILE"
 366     vbm "GNUCU_DIGESTS set to:""$GNUCU_DIGESTS"
 367     checkExecutables "$DIGEST_ALGO"; # Check that specified alogirthm command available.
 368     if [[ "$GNUCU_DIGESTS" =~ .*"$DIGEST_ALGO".* ]]; then
 369         vbm "DEBUG:Confirmed to be a valid GNU Coreutils command:""$DIGEST_ALGO";
 370     else
 371         vbm "ERROR:Not a valid GNU coreutils command:""$DIGEST_ALGO";
 372         exit 1;
 373     fi # Check specified algo against GNUCU_DIGESTS. See [2].
 374
 375     # Perform work
 376     OUTPUT="$("$DIGEST_ALGO" "$TARGET_FILE" | awk '{print $1}')"
 377     vbm "DEBUG:Calculated digest using $DIGEST_ALGO is:""$OUTPUT"
 378
 379     # Output results
 380     echo "$OUTPUT"
 381
 382     # End function
 383     vbm "DEBUG:getGnucuDigest function ended."
 384     return 0; # Function finished.
 385 } # Calculate GNUCoreutils digest
 386
 387
 388 #== Main Program Definition ==
 389 main() {
 390     # Usage: main "$@"    # See [1].
 391     # Input: unspecified (note: all Global Constants declared at beginning of script assumed to be available)
 392     #   OPTION_VERBOSE   (used by vbm, set by processArguments)  (ex: "true", "false")
 393     #   DIGEST_ALGO      (used by getGnucuDigest, set by processArguments) (ex: "md5sum")
 394     # Output: unspecified
 395     # Script function dependencies:
 396     #   - echoerr          for displaying errors via stderr
 397     #   - vbm              for displaying verbose messages if OPTION_VERBOSE is "true"
 398     #   - processArguments for setting OPTION_VERBOSE
 399     #   - checkExecutables for checking that specified commands are available
 400     # External dependencies: bash (5.0.3), echo
 401     # Last modified: 2020-05-04T18:44Z
 402     # Last modified by: Steven Baltakatei Sandoval
 403     # License: GPLv3+
 404     # Ref./Attrib.:
 405     #  [1]: ErichBSchulz (2011-11-20). [How to correctly pass bash script arguments to functions](https://stackoverflow.com/a/8198970). Licensed CC BY-SA 4.0.
 406
 407     # Initialize function
 408     processArguments "$@" # Process arguments.
 409     vbm "DEBUG:main function called."
 410     vbm "DEBUG:main function arguments are:""$@"
 411     checkExecutables "echo" "date" "cut" "awk" "grep" # Confirm that executables necessary to run are available. Exit if any fail.
 412
 413     # Process inputs
 414     # If DIRIN1 unset and global variable BK_FILEHASHLIST_DIR set and is dir, then set DIRIN1 to BK_FILEHASHLIST_DIR.
 415     if ! [ -v DIRN1 ] && [ -v BK_FILEHASHLIST_DIR ] && [ -d "$BK_FILEHASHLIST_DIR" ]; then
 416         DIRIN1="$BK_FILEHASHLIST_DIR";
 417         vbm "DEBUG:DIRN1 not set, BK_FILEHASHLIST_DIR is dir, so setting DIRIN1 to BK_FILEHASHLIST_DIR:""$BK_FILEHASHLIST_DIR";
 418     fi
 419
 420     # Set defaults
 421     if ! [ -v DIGEST_ALGO ]; then # If DIGEST_ALGO is not set then set it to default value of "b2sum"
 422         DIGEST_ALGO="b2sum";
 423         vbm "DEBUG:DIGEST_ALGO not set. Setting to default value:""$DIGEST_ALGO"
 424     fi
 425
 426
 427     # if [ -v FILEIN1 ]; then # VERBOSE: Display contents of FILEIN1 if FILEIN1 has been set.
 428     #   vbm "DEBUG:main function detects input file:""$FILEIN1" ;
 429     #   vbm "DEBUG:contents of following file is displayed below:""$FILEIN1" ;
 430     #   if [ "$OPTION_VERBOSE" == "true" ]; then # display FILEIN1 contents via cat if verbose mode specified
 431     #       echoerr "========""$FILEIN1"" START""========" ;
 432     #       cat "$FILEIN1" 1>&2 ;
 433     #       echoerr "========""$FILEIN1"" END""========" ;
 434     #   fi
 435     # fi
 436
 437
 438     # Perform work
 439     DIGEST="$(getGnucuDigest "$DIGEST_ALGO" "$FILEIN1")" # Calculate digest of FILEIN1
 440     vbm "DEBUG:Hash of $FILEIN1 is:""$DIGEST"
 441     vbm "DEBUG:Value of DIGEST is:""$DIGEST"
 442     vbm "DEBUG:Value of DIRIN1 is:""$DIRIN1"
 443     OUTPUT="$(grep -ri "$DIGEST" "$DIRIN1")" # Search contents of DIRIN1 for pattern DIGEST, save results to OUTPUT.
 444
 445     # Output results
 446     echo -e "$OUTPUT"
 447
 448     if [ -v FILEOUT1 ]; then  # if FILEOUT1 set, write to this file.
 449         vbm "DEBUG:main function detects FILEOUT1 set to:""$FILEOUT1" ;
 450         echo -e "$OUTPUT" > "$FILEOUT1" ;
 451         vbm "DEBUG:main funtion wrote OUTPUT to:""$FILEOUT1" ;
 452     elif [ -v DIROUT1 ]; then  # else if DIROUT1 set, set FILEOUT1 to timestamped filename, combine into PATHOUT1, write output to PATHOUT1.
 453         vbm "DEBUG:main function detects DIROUT1 set to:""$DIROUT1" ;
 454         FILEOUT1="$SCRIPT_TIME_SHORT".."$(basename "$0")".txt
 455         PATHOUT1="$DIROUT1"/"$FILEOUT1"
 456         echo -e "$OUTPUT" > $PATHOUT1 ;
 457         vbm "DEBUG:main function wrote output file to:""$PATHOUT1" ;
 458     fi
 459
 460     # End function
 461     vbm "DEBUG:main function ended."
 462     return 0; # Function finished.
 463 }
 464
 465 #== Perform work and exit ==
 466 main "$@" # Run main function.
 467 exit 0;