style(unitproc):appendFileTar():VAR_NAME to varName
[BK-2020-03.git] / unitproc / bktemp-checkMakeTar
1 #!/bin/bash
2 # Desc: Checks that a valid tar archive exists, creates one otherwise
3
4 #===BEGIN Declare local script functions===
5 yell() { echo "$0: $*" >&2; } #o Yell, Die, Try Three-Fingered Claw technique
6 die() { yell "$*"; exit 111; } #o Ref/Attrib: https://stackoverflow.com/a/25515370
7 try() { "$@" || die "cannot $*"; } #o
8 checkMakeTar() {
9 # Desc: Checks that a valid tar archive exists, creates one otherwise
10 # Usage: checkMakeTar [ path ]
11 # Version: 1.0.2
12 # Input: arg1: path of tar archive
13 # Output: exit code 0 : tar readable
14 # exit code 1 : tar missing; created
15 # exit code 2 : tar not readable; moved; replaced
16 # Depends: bash 5, date 8, tar 1, try()
17 local pathTar returnFlag0 returnFlag1 returnFlag2
18 pathTar="$1";
19
20 # Check if file is a valid tar archive
21 if tar --list --file="$pathTar" 1>/dev/null 2>&1; then
22 ## T1: return success
23 returnFlag0="tar valid";
24 else
25 ## F1: Check if file exists
26 if [[ -f "$pathTar" ]]; then
27 ### T: Rename file
28 try mv "$pathTar" "$pathTar""--broken--""$(date +%Y%m%dT%H%M%S)" && \
29 returnFlag1="tar moved";
30 else
31 ### F: -
32 :
33 fi;
34 ## F2: Create tar archive, return 0
35 try tar --create --file="$pathTar" --files-from=/dev/null && \
36 returnFlag2="tar created";
37 fi;
38
39 # Determine function return code
40 if [[ "$returnFlag0" = "tar valid" ]]; then
41 return 0;
42 elif [[ "$returnFlag2" = "tar created" ]] && ! [[ "$returnFlag1" = "tar moved" ]]; then
43 return 1; # tar missing so created
44 elif [[ "$returnFlag2" = "tar created" ]] && [[ "$returnFlag1" = "tar moved" ]]; then
45 return 2; # tar not readable so moved; replaced
46 fi;
47 } # checks if arg1 is tar; creates one otherwise
48 #===END Declare local script functions===
49
50 #====BEGIN sample code====
51 #myFile="/tmp/$(date +%s)..tar"
52 myFile="/tmp/$(date +%Y%m%d).tar"
53 if [[ -f "$myFile" ]]; then yell "$myFile already exists."; else yell "$myFile doesn't yet exist."; fi
54 if checkMakeTar "$myFile"; then
55 yell "checkMakeTar() function run and exited:$?";
56 else
57 yell "checkMakeTar() function run and exited:$?";
58 fi
59
60 if [[ -f "$myFile" ]]; then
61 yell "Now exists :$myFile";
62 ls -l "$myFile";
63 else
64 yell "Does not exist:$myFile";
65 ls -l "$myFile";
66 fi
67 #====END sample code====
68
69 # Author: Steven Baltakatei Sandoval
70 # License: GPLv3+