unitproc/bkt-insertStr

   1 #!/usr/bin/env bash
   2 # Desc: Insert string into provided string
   3
   4 yell() { echo "$0:${FUNCNAME[*]}: $*" >&2; }
   5 die() { yell "$*"; exit 111; }
   6 must() { "$@" || die "cannot $*"; }
   7
   8 insertStr() {
   9     # Desc: Inserts a
  10     # Input: arg1: str   str_rec  String to receive insertion
  11     #        arg2: int   pos      Insertion position (0 = append to front)
  12     #        arg3: str   str_ins  String to be inserted
  13     # Output: stdout:    Combined string
  14     # Version: 0.0.1
  15     # Depends: BK-2020-03: yell(), die(), must()
  16     # Ref/Attrib: * BK-2020-03: https://gitlab.com/baltakatei/baltakatei-exdev/
  17
  18     local str_rec pos str_ins;
  19
  20     # Check args
  21     if [[ $# -ne 3 ]]; then
  22         yell "ERROR:Invalid argument count:$#";
  23         return 1; fi;
  24     re='^[0-9]+$';
  25     if [[ ! "$2" =~ $re ]]; then
  26         yell "ERROR:Not an int:$2";
  27         return 1; fi;
  28     str_rec="$1";
  29     pos="$2";
  30     str_ins="$3";
  31
  32     # Calculate string stats
  33     len_str_rec="${#str_rec}";
  34     len_str_ins="${#str_ins}";
  35
  36     # Form prefix
  37     pfx_pos_start="0";
  38     pfx_len="$pos";
  39     pfx="${str_rec:$pfx_pos_start:$pfx_len}";
  40
  41     # Form suffix
  42     sfx_pos_start="$(( pos ))";
  43     sfx_len="$(( len_str_rec - pos ))";
  44     sfx="${str_rec:$sfx_pos_start:$sfx_len}";
  45
  46     # Print output to stdout
  47     printf "%s%s%s\n" "$pfx" "$str_ins" "$sfx";
  48 }; # Insert string provided at indicated position via stdout
  49
  50
  51 # Tests
  52 printf "\"%s\" should read \"foobarbaz\"\n" "$(insertStr "foobaz" 3 "bar";)";
  53
  54 insertStr "foobaz" 0 "bar";
  55 insertStr "foobaz" 1 "bar";
  56 insertStr "foobaz" 2 "bar";
  57 insertStr "foobaz" 3 "bar";
  58 insertStr "foobaz" 4 "bar";
  59 insertStr "foobaz" 5 "bar";
  60 insertStr "foobaz" 6 "bar";
  61 insertStr "foobaz" 7 "bar";
  62 insertStr "foobaz" 999 "bar";