chore(bktemplate):Remove date from file
[BK-2020-03.git] / unitproc / bktemplate
1 #!/bin/bash
2
3 # Author: Steven Baltakatei Sandoval
4 # Description: Template for bash scripts.
5 # Note: Use hide-show-block function to aid readability. (ex: https://www.emacswiki.org/emacs/HideShow ).
6
7 #== Variable Initialization ==
8
9 #== Global constants ==
10 SCRIPT_TTL=10 # Limit script life to this in seconds.
11 PATH="/usr/local/bin/:$PATH" # Add user binary executable directory to PATH.
12 PATH="/opt/bktei:$PATH" # Add 'optional' executable directory to PATH.
13 SCRIPT_HOSTNAME=$(hostname) # Save hostname of system running this script.
14 SCRIPT_VERSION="bktemplate.sh 0.0.0" # Define version of script. Used by function 'showVersion'.
15 SCRIPT_TIME_SHORT="$(date +%Y%m%dT%H%M%S%z)" # Save current date & time in ISO-8601 format (YYYYmmddTHHMMSS+zzzz).
16 SCRIPT_DATE_SHORT="$(date +%Y%m%d)" # Save current date in ISO-8601 format.
17
18 #== Function Definitions ==
19
20 # Yell, Die, Try Three-Fingered Claw technique
21 # Ref/Attrib: https://stackoverflow.com/a/25515370
22 yell() { echo "$0: $*" >&2; }
23 die() { yell "$*"; exit 111; }
24 try() { "$@" || die "cannot $*"; }
25
26
27 echoerr() {
28 # Usage: echo [ arguments ]
29 # Description: Prints provided arguments to stderr.
30 # Input: unspecified
31 # Output: stderr
32 # Script function dependencies: none
33 # External function dependencies: echo
34 # Last modified: 2020-04-11T21:16Z
35 # Last modified by: Steven Baltakatei Sandoval
36 # License: GPLv3+
37 # Ref./Attrib:
38 # [1]: # Roth, James (2010-06-07). ["How to print text to stderr instead of stdout"](https://stackoverflow.com/a/2990533). Licensed CC BY-SA 4.0.
39
40 echo "$@" 1>&2; # Define stderr echo function. See [1].
41 return 0; # Function finished.
42 } # Define stderr message function.
43 vbm() {
44 # Usage: vbm "DEBUG:verbose message here"
45 # Description: Prints verbose message ("vbm") to stderr if OPTION_VERBOSE is set to "true".
46 # Input:
47 # - OPTION_VERBOSE variable set by processArguments function. (ex: "true", "false")
48 # - "$@" positional arguments fed to this function.
49 # Output: stderr
50 # Script function dependencies: echoerr
51 # External function dependencies: echo
52 # Last modified: 2020-04-11T23:57Z
53 # Last modified by: Steven Baltakatei Sandoval
54 # License: GPLv3+
55 # Ref./Attrib:
56
57 if [ "$OPTION_VERBOSE" == "true" ]; then
58 FUNCTION_TIME=$(date --iso-8601=ns); # Save current time in nano seconds.
59 echoerr "[$FUNCTION_TIME] ""$@"; # Display argument text.
60 fi
61
62 # End function
63 return 0; # Function finished.
64 } # Verbose message display function.
65 run() {
66 # Usage: run [cmd]
67 # Description: Runs command; reports success if command exit code 0; exits otherwise.
68 # Input: none
69 # Output: stdout
70 # Script function dependencies: none
71 # Last modified: 2020-06-19T22:09Z
72 # Last modified by: Steven Baltakatei Sandoval
73 # License: GPLv3+
74 # Ref.Attrib: https://stackoverflow.com/a/18880585
75 cmd_output=$(eval $1)
76 return_value=$?
77 if [ $return_value != 0 ]; then
78 echo "Command $1 failed";
79 exit -1;
80 else
81 echo "output: $cmd_output";
82 echo "Command succeeded.";
83 fi
84 return $return_value
85 } #
86 showUsage() {
87 # Usage: showUsage
88 # Description: Displays script usage information.
89 # Input: none
90 # Output: stderr
91 # Script function dependencies: echoerr
92 # External dependencies: bash (5.0.3), echo
93 # Last modified: 2020-05-04T16:11Z
94 # Last modified by: Steven Baltakatei Sandoval
95 # License: GPLv3+
96 # Ref./Attrib.:
97
98 echoerr "USAGE:"
99 echoerr " bktemplate.sh [ options ]"
100 echoerr
101 echoerr "OPTIONS:"
102 echoerr " -h, --help"
103 echoerr " Display help information."
104 echoerr
105 echoerr " --version"
106 echoerr " Display script version."
107 echoerr
108 echoerr " -v, --verbose"
109 echoerr " Display debugging info."
110 echoerr
111 echoerr " -o, --output-file [ file ]"
112 echoerr " Specify output file."
113 echoerr
114 echoerr " -i, --input-file [ file ]"
115 echoerr " Specify input file."
116 echoerr
117 echoerr " -o, --output-dir [ directory ]"
118 echoerr " Specify output directory."
119 echoerr
120 echoerr " -i, --input-dir [ directory ]"
121 echoerr " Specify input directory."
122 echoerr
123
124 # End function
125 return 0; # Function finished.
126 } # Display information on how to use this script.
127 showVersion() {
128 # Usage: showVersion
129 # Descriptoin: Displays script version and license information.
130 # Input: unspecified
131 # Output: stderr
132 # Script function dependencies: echoerr
133 # External function dependencies: echo
134 # Last modified: 2020-04-11T23:57Z
135 # Last modified by: Steven Baltakatei Sandoval
136 # License: GPLv3+
137 # Ref./Attrib:
138
139 # Initialize function
140 vbm "DEBUG:showVersion function called."
141
142 # Perform work
143 OUTPUT="$SCRIPT_VERSION"
144
145 # Display results
146 echoerr "$OUTPUT";
147
148 # End function
149 vbm "DEBUG:showVersion function ended."
150 return 0; # Function finished.
151 } # Display script version.
152 processArguments() {
153 # Usage: processArguments "$@"
154 # Description: Processes provided arguments in order to set script option variables useful for
155 # changing how other functions behave. For example, it may:
156 # 1. Activate verbose mode
157 # Input: "$@" (list of arguments provided to the function)
158 # Output: Sets following variables used by other functions:
159 # OPTION_VERBOSE Indicates verbose mode enable status. (ex: "true", "false")
160 # DIROUT1 Path to output directory.
161 # FILEOUT1 Path to output file.
162 # DIRIN1 Path to input directory.
163 # FILEIN1 Path to input file.
164 # OPTION_FILEOUT1_OVERWRITE Indicates whether file FILEOUT1 should be overwritten (ex: "true", "false')
165 # Script function dependencies:
166 # - echoerr Displays messages to stderr.
167 # - vbm Displays messsages to stderr if OPTION_VERBOSE set to "true".
168 # External dependencies: bash (5.0.3), echo
169 # Last modified: 2020-05-04T14:41Z
170 # Last modified by: Steven Baltakatei Sandoval
171 # License: GPLv3+
172 # Ref./Attrib.:
173 # [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
174
175 # Initialize function
176 #vbm "DEBUG:processArguments function called."
177
178 # Perform work
179 while [ ! $# -eq 0 ]; do # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
180 #1>&2 echo "DEBUG:Starting processArguments while loop." # Debug stderr message. See [1].
181 #1>&2 echo "DEBUG:Provided arguments are:""$@" # Debug stderr message. See [1].
182 case "$1" in
183 -h | --help) showUsage; exit 1;; # Display usage.
184 --version) showVersion; exit 1;; # Show version
185 -v | --verbose) OPTION_VERBOSE="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
186 -i | --input-file) # Define input file path
187 if [ -f "$2" ]; then # If $2 is file that exists, set FILEIN1 to $2, pop $2.
188 FILEIN1="$2";
189 shift;
190 vbm "DEBUG:Input file FILEIN1 set to:""$2";
191 else
192 echoerr "ERROR: Specified input file does not exist:""$2";
193 echoerr "Exiting.";
194 exit 1;
195 fi ;;
196 -I | --input-dir) # Define input directory path
197 if [ -d "$2" ]; then # If $2 is dir that exists, set DIRIN1 to $2, pop $2.
198 DIRIN1="$2";
199 shift;
200 vbm "DEBUG:Input directory DIRIN1 set to:""$2";
201 else # Display error if $2 is not a valid dir.
202 echoerr "ERROR:Specified input directory does not exist:""$2";
203 echoerr "Exiting.";
204 exit 1;
205 fi ;;
206 -o | --output-file) # Define output file path
207 if [ -f "$2" ]; then # If $2 is file that exists, prompt user to continue to overwrite, set FILEOUT1 to $2, pop $2.
208 echoerr "Specified output file $2 already exists. Overwrite? (y/n):"
209 read m; case $m in
210 y | Y | yes) OPTION_FILEOUT1_OVERWRITE="true";;
211 n | N | no) OPTION_FILEOUT1_OVERWRITE="false";;
212 *) echoerr "Invalid selection. Exiting."; exit 1;;
213 esac
214 if [ "$OPTION_FILEOUT1_OVERWRITE" == "true" ]; then
215 FILEOUT1="$2";
216 shift;
217 vbm "DEBUG:Output file FILEOUT1 set to:""$2";
218 else
219 echoerr "ERORR:Exiting in order to not overwrite output file:""$FILEOUT1";
220 exit 1;
221 fi
222 else
223 FILEOUT1="$2";
224 shift;
225 vbm "DEBUG:Output file FILEOUT1 set to:""$2";
226 fi ;;
227 -O | --output-dir) # Define output directory path
228 if [ -d "$2" ]; then # If $2 is dir that exists, set DIROUT1 to $2, pop $2
229 DIROUT1="$2";
230 shift;
231 vbm "DEBUG:Output directory DIROUT1 set to:""$2";
232 else
233 echoerr "ERROR:Specified output directory is not valid:""$2";
234 echoerr "Exiting.";
235 exit 1;
236 fi ;;
237 *) echoerr "ERROR: Unrecognized argument."; exit 1;; # Handle unrecognized options. See [1].
238 esac
239 shift
240 done
241
242 # End function
243 vbm "DEBUG:processArguments function ended."
244 return 0; # Function finished.
245 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
246 checkExecutables() {
247 # Usage: checkExecutables [ command1 ] [ command2 ] [...] [ commandN ]
248 # Description: Checks that provided commands exist and displays those that do not exist.
249 # Input:
250 # - command names (arguments)
251 # Output: commands that don't exist (stderr)
252 # Script function dependencies:
253 # - echoerr for displaying errors via stderr
254 # - processArguments for setting OPTION_VERBOSE
255 # - vbm for displaying verbose messages if OPTION_VERBOSE is "true"
256 # External dependencies: bash (5.0.3), command
257 # Last modified: 2020-04-11T23:59Z
258 # Last modified by: Steven Baltakatei Sandoval
259 # License: GPLv3+
260 # Ref./Attrib.:
261 # [1]: SiegeX (2010-12-12). ["Difference between return and exit in Bash functions."](https://stackoverflow.com/a/4419971). Licensed CC BY-SA 4.0.
262 # [2]: Darryl Hein (2009-12-23). ["Add a new element to an array without specifying the index in Bash"](https://stackoverflow.com/a/1951523). Licensed CC BY-SA 4.0.
263 # [3]: kojiro (2012-10-03). ["Convert command line arguments into an array in Bash"](https://stackoverflow.com/a/12711853)
264 # [4]: niieani (2016-01-12). ["How to copy an array in Bash?"](https://stackoverflow.com/a/34733375/10850071). Licensed CC BY-SA 4.0.
265
266 # Initialize function
267 vbm "DEBUG:checkExecutables function called."
268 declare -a candidateCommandsNames # Initialize array for storing positional arguments provided to this function.
269 candidateCommandsNames=("$@") # Save positional arguments to variable as string. See [3].
270 vbm "DEBUG:candidateCommandsNames:""$@"
271 vbm "DEBUG:candidateCommandsNames[0]:""${candidateCommandsNames[0]}"
272 vbm "DEBUG:candidateCommandsNames[1]:""${candidateCommandsNames[1]}"
273 vbm "DEBUG:candidateCommandsNames[2]:""${candidateCommandsNames[2]}"
274 declare -a outputInvalidCommandsArray # Initialize arary for storing names of invalid commands.
275 declare -a outputValidCommandsArray # Initialize array for storing names of valid commands.
276
277 # Perform work
278 for candidateCommandName in "${candidateCommandsNames[@]}"; do # Search through all space-delimited text for valid commands.
279 if command -v "$candidateCommandName" 1>/dev/null 2>/dev/null; then # Check if a command is valid or not.
280 outputValidCommandsArray+=("$candidateCommandName") ; # See [2].
281 vbm "DEBUG:Adding $candidateCommandName to outputValidCommandsArray."
282 else
283 outputInvalidCommandsArray+=("$candidateCommandName") ; # See [2].
284 vbm "DEBUG:Adding $candidateCommandName to outputInvalidCommandsArray."
285 fi
286 done
287
288 # Output results
289 if [ ${#outputInvalidCommandsArray[@]} -gt 0 ]; then # if number of elements in outputInvalidCommandsArray greater than 0, then display offending commands and exit 1.
290 echoerr "ERROR: Invalid commands found:""${outputInvalidCommandsArray[@]}"; # display invalid commands as error
291 exit 1; # See [1].
292 elif [ ${#outputInvalidCommandsArray[@]} -eq 0 ]; then # if number of elements in outputInvalidCommandsArray equals zero, then return 0.
293 vbm "DEBUG: Valid commands are:""${outputValidCommandsArray[@]}"; # display valid commands if verbose mode enabled
294 return 0; # See [1].
295 else
296 echoerr "ERROR: Check outputInvalidCommandsArray.";
297 fi
298
299 # End function
300 vbm "DEBUG:checkExecutables function ended."
301 return 0; # Function finished.
302 } # Check that certain executables exist.
303 updateTimeConstants() {
304 # Usage: updateTimeConstants
305 # Description: Updates time-related variables for use by other scripts.
306 # Input: (none)
307 # Output: Sets following variables:
308 # TIME_CURRENT Current time in long ISO-8601 format. (ex: YYYY-mm-ddTHH:MM:SS+ZZZZ)
309 # TIME_CURRENT_SHORT Current time in short ISO-8601 format. (ex: YYYYmmddTHHMMSS+ZZZZ)
310 # DATE_CURRENT Current date in ISO-8601 format. (ex: YYYY-mm-dd)
311 # DATE_CURRENT_SHORT Current date in short ISO-8601 format. (ex: YYYYmmdd)
312 # DATE_TOMORROW Tomorrow's date in ISO-8601 format. (ex: YYYY-mm-dd)
313 # TIME_NEXT_MIDNIGHT Time of tomorrow's midnight in long (ex: YYYY-mm-ddTHH:MM:SS+ZZZZ)
314 # ISO-861 format.
315 # SEC_TIL_MIDNIGHT Seconds until next midnight.
316 # Script function dependencies:
317 # - echoerr for displaying errors via stderr
318 # - processArguments for setting OPTION_VERBOSE
319 # - vbm for displaying verbose messages if OPTION_VERBOSE is "true"
320 # External dependencies: bash (5.0.3), date, echo
321 # Last modified: 2020-04-11T23:59Z
322 # Last modified by: Steven Baltakatei Sandoval
323 # License: GPLv3+
324 # Ref./Attrib.:
325
326 # Initialize function
327 vbm "DEBUG:updateTimeConstants function called."
328
329 # Perform work
330 TIME_CURRENT="$(date --iso-8601=seconds)" ;
331 TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)"
332 DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ;
333 DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ;
334 DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ;
335 TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ;
336 SECONDS_UNTIL_NEXT_MIDNIGHT="$(( $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT") ))" ;
337
338 # End function
339 vbm "DEBUG:updateTimeConstants function ended."
340 return 0; # Function finished.
341 } # Update time constants
342
343 #== Main Program Definition ==
344 main() {
345 # Usage: main "$@" # See [1].
346 # Input: unspecified (note: all Global Constants declared at beginning of script assumed to be available)
347 # OPTION_VERBOSE (used by vbm, set by processArguments) (ex: "true", "false")
348 # Output: unspecified
349 # Script function dependencies:
350 # - echoerr for displaying errors via stderr
351 # - vbm for displaying verbose messages if OPTION_VERBOSE is "true"
352 # - processArguments for setting OPTION_VERBOSE
353 # - checkExecutables for checking that specified commands are available
354 # External dependencies: bash (5.0.3), echo
355 # Last modified: 2020-05-04T16:50Z
356 # Last modified by: Steven Baltakatei Sandoval
357 # License: GPLv3+
358 # Ref./Attrib.:
359 # [1]: ErichBSchulz (2011-11-20). [How to correctly pass bash script arguments to functions](https://stackoverflow.com/a/8198970). Licensed CC BY-SA 4.0.
360
361 # Initialize function
362 processArguments "$@" # Process arguments.
363 vbm "DEBUG:main function called."
364 vbm "DEBUG:main function arguments are:""$@"
365 checkExecutables "echo" "date" "cut" "awk" # Confirm that executables necessary to run are available. Exit if any fail.
366
367 # Process inputs
368 if [ -v FILEIN1 ]; then # VERBOSE: Display contents of FILEIN1 if FILEIN1 has been set.
369 vbm "DEBUG:main function detects input file:""$FILEIN1" ;
370 vbm "DEBUG:contents of following file is displayed below:""$FILEIN1" ;
371 if [ "$OPTION_VERBOSE" == "true" ]; then # display FILEIN1 contents via cat if verbose mode specified
372 echoerr "========""$FILEIN1"" START""========" ;
373 cat "$FILEIN1" 1>&2 ;
374 echoerr "========""$FILEIN1"" END""========" ;
375 fi
376 fi
377
378 # Perform work
379 OUTPUT="$OUTPUT""Hello world.\n"
380 if [ -v FILEIN1 ]; then
381 OUTPUT="$OUTPUT""The b2sum hash of $FILEIN1 is: $(b2sum "$FILEIN1" | awk '{print $1}').\n";
382 fi
383 OUTPUT="$OUTPUT""The current time is:""$SCRIPT_TIME_SHORT\n"
384
385 # Output results
386 echo -e "$OUTPUT"
387
388 if [ -v FILEOUT1 ]; then # if FILEOUT1 set, write to this file.
389 vbm "DEBUG:main function detects output file:""$FILEOUT1" ;
390 echo -e "$OUTPUT" > "$FILEOUT1" ;
391 vbm "DEBUG:main funtion wrote OUTPUT to:""$FILEOUT1" ;
392 elif [ -v DIROUT1 ]; then # else if DIROUT1 set, set FILEOUT1 to timestamped filename, combine into PATHOUT1, write output to PATHOUT1.
393 vbm "DEBUG:main function detects output directory:""$DIROUT1" ;
394 FILEOUT1="$SCRIPT_TIME_SHORT"..output
395 PATHOUT1="$DIROUT1"/"$FILEOUT1"
396 echo -e "$OUTPUT" > $PATHOUT1 ;
397 vbm "DEBUG:main function wrote output file to:""$PATHOUT1" ;
398 fi
399
400 # End function
401 vbm "DEBUG:main function ended."
402 return 0; # Function finished.
403 }
404
405 #== Perform work and exit ==
406 main "$@" # Run main function.
407 exit 0;