style(unitproc/):Shorten names of template prefix (bktemp -> bkt)

[BK-2020-03.git] / unitproc / bkt-checkMakeTar

diff --git a/unitproc/bkt-checkMakeTar b/unitproc/bkt-checkMakeTar
new file mode 100644 (file)
index 0000000..07cec78
--- /dev/null
+++ b/unitproc/bkt-checkMakeTar
@@ -0,0 +1,70 @@
+#!/bin/bash
+# Desc: Checks that a valid tar archive exists, creates one otherwise
+
+#===BEGIN Declare local script functions===
+yell() { echo "$0: $*" >&2; }      #o Yell, Die, Try Three-Fingered Claw technique
+die() { yell "$*"; exit 111; }     #o Ref/Attrib: https://stackoverflow.com/a/25515370
+try() { "$@" || die "cannot $*"; } #o
+checkMakeTar() {
+    # Desc: Checks that a valid tar archive exists, creates one otherwise
+    # Usage: checkMakeTar [ path ]
+    # Version: 1.0.2
+    # Input: arg1: path of tar archive
+    # Output: exit code 0 : tar readable
+    #         exit code 1 : tar missing; created
+    #         exit code 2 : tar not readable; moved; replaced
+    # Depends: bash 5, date 8, tar 1, try()
+    local pathTar returnFlag0 returnFlag1 returnFlag2
+    pathTar="$1";
+
+    # Check if file is a valid tar archive
+    if tar --list --file="$pathTar" 1>/dev/null 2>&1; then
+       ## T1: return success
+       returnFlag0="tar valid";
+    else
+       ## F1: Check if file exists
+       if [[ -f "$pathTar" ]]; then
+           ### T: Rename file
+           try mv "$pathTar" "$pathTar""--broken--""$(date +%Y%m%dT%H%M%S)" && \
+               returnFlag1="tar moved";
+       else
+           ### F: -
+           :
+       fi;
+       ## F2: Create tar archive, return 0
+       try tar --create --file="$pathTar" --files-from=/dev/null && \
+           returnFlag2="tar created";
+    fi;
+    
+    # Determine function return code
+    if [[ "$returnFlag0" = "tar valid" ]]; then
+       return 0;
+    elif [[ "$returnFlag2" = "tar created" ]] && ! [[ "$returnFlag1" = "tar moved" ]]; then
+       return 1; # tar missing so created
+    elif [[ "$returnFlag2" = "tar created" ]] && [[ "$returnFlag1" = "tar moved" ]]; then
+       return 2; # tar not readable so moved; replaced
+    fi;
+} # checks if arg1 is tar; creates one otherwise
+#===END Declare local script functions===
+
+#====BEGIN sample code====
+#myFile="/tmp/$(date +%s)..tar"
+myFile="/tmp/$(date +%Y%m%d).tar"
+if [[ -f "$myFile" ]]; then yell "$myFile already exists."; else yell "$myFile doesn't yet exist."; fi
+if checkMakeTar "$myFile"; then
+    yell "checkMakeTar() function run and exited:$?";
+else
+    yell "checkMakeTar() function run and exited:$?";
+fi
+    
+if [[ -f "$myFile" ]]; then
+    yell "Now exists    :$myFile";
+    ls -l "$myFile";
+else
+    yell "Does not exist:$myFile";
+    ls -l "$myFile";
+fi
+#====END sample code====
+
+# Author: Steven Baltakatei Sandoval
+# License: GPLv3+