在Linux中如何檢查連續模式中是否有2種不同的模式

Question

我有一個正在驗證的ASCII文本文件。 該文件包含2種類型的上下文：

Necessary Context: One which should be present at least once in its exact position.
Optional Context: One which may or may not be present, but if present should hold its proper place.

文件的詳細外觀：

[INDEX] <-- optional context, but if present should be the first context immediately followed by [FEATURE_ID], else file invalid
[FEATURE_ID] <-- necessary context and should always be immediately followed by [FEATURE_REV], else file is invalid. If [INDEX] context there then this should be the second CONTEXT in file else first.
[FEATURE_REV] <-- necessary context (must exist one per FEATURE_ID) and should always be immediately after [FEATURE_ID], else file is invalid.
[PRL_ID] <-- optional context, but if present should always be immediately after [FEATURE_REV], else file invalid
[NO_OF_BYTES] <--optional context, but if present, should always be immediately after [PRL_ID] if it is present, else immediately after [FEATURE_REV] if [PRL_ID] not present. Otherwise file invalid.
[NO_OF_SIGNIF_BITS] <-- optional context, but if present should always be between [NO_OF_BYTES] ( can be only present if [NO_OF_BYTES] present else not) and [CRC], else file invalid
[CRC] <-- necessary context,(must exist one per FEATURE_ID and FEATURE_REV). This is always the last context.

請注意，有效文件中可能有多個[FEATURE_ID]上下文，並且在所有情況下，領導該文件的其他上下文應遵循相同的占位規則。 像這樣：

Validfile_1:

[FEATURE_ID]
[FEATURE_REV]
[CRC]

[INDEX]
[FEATURE_ID]
[FEATURE_REV]
[CRC]

Validfile_2:

[FEATURE_ID]
[FEATURE_REV]
[NO_OF_BYTES]
[CRC]

[INDEX]
[FEATURE_ID]
[FEATURE_REV]
[PRL_ID]
[NO_OF_BYTES]
[NO_OF_SIGNIF_BITS]
[CRC]

Validfile_3

[FEATURE_ID]
[FEATURE_REV]
[CRC]

Invalidfile_1 (order of contexts not ok):

[FEATURE_ID]
[INDEX]
[FEATURE_REV]
[NO_OF_BYTES]
[CRC]
[PRL_ID]

Invalidfile_2(FEATURE_REV or CRC can never exist without a FEATURE_ID):

[FEATURE_REV]
[NO_OF_BYTES]
[CRC]

Invalidfile_3 ( NO_OF_SIGNIF_BITS cannot exist without NO_OF_BYTES)

[FEATURE_ID]
[FEATURE_REV]
[NO_OF_SIGNIF_BITS]
[CRC]

我正在嘗試通過多個if else語句和egreps在linux腳本中實現這egreps ，但是代碼行變得越來越復雜。

我要使用的代碼：

f_id_c=`egrep "[ ]*\[FEATURE_ID=[0-9].*\][ ]*" $1 | wc -l`
f_rev_c=`egrep "[ ]*\[FEATURE_REV=[0-9].*\][ ]*" $1 | wc -l`
crc_c=`egrep "[ ]*\[CRC\][ ]*" $1 | wc -l`
[[ $((f_id_c)) -eq 0 ]] && { echo "Invalid! No [FEATURE_ID=] context defined in profile file !"; exit 1; }
[[ $((f_rev_c)) -ne $((f_id_c)) ]] && { echo "Invalid! Not all [FEATURE_REV=] contexts have leading [FEATURE_ID=] defined"; exit 1; }
[[ $((crc_c)) -ne $((f_id_c)) ]] && { echo "Invalid! Not all [CRC] contexts have leading [FEATURE_ID=] defined"; exit 1; }
for (i=0;i<f_id_c;i++)
  do
    // Have a check with SED that will confirm there is a [FEATURE_REV=] immediately following [FEATURE_ID=]
  done

有人可以建議一個緊湊的awk script或sed操作，使我可以實現上述所有驗證。

Answer 1

您將需要這樣的FSM：

$ cat tst.awk
BEGIN {
    # define the allowed state transitions
    ns["IDLE","INDEX"]
    ns["IDLE","FEATURE_ID"]
    ns["INDEX","FEATURE_ID"]
    ns["FEATURE_ID","FEATURE_REV"]
    ns["FEATURE_REV","PRL_ID"]
    ns["FEATURE_REV","NO_OF_BYTES"]
    ns["FEATURE_REV","CRC"]
    ns["PRL_ID","NO_OF_BYTES"]
    ns["PRL_ID","CRC"]
    ns["NO_OF_BYTES","NO_OF_SIGNIF_BITS"]
    ns["NO_OF_BYTES","CRC"]
    ns["NO_OF_SIGNIF_BITS","CRC"]
    ns["CRC","INDEX"]
    ns["CRC","FEATURE_ID"]

    # create a regexp of the state names for use in match()
    for (state in ns) {
        sub(SUBSEP".*","",state)
        if (!seen[state]++) {
            states = states (states ? "|" : "") state
        }
    }

    # set the initial state
    state = "IDLE"
}

# parse the input
match($0,states) {
    nextState = substr($0,RSTART,RLENGTH)
    if ( ! ((state,nextState) in ns) ) {
        print "ERROR", NR, state, nextState, $0 | "cat>&2"
        exit 1
    }
    state = nextState
}

針對發布的樣本輸入文件運行時：

$ cat file
....
[FEATURE_ID]
[FEATURE_REV]
...
...
[CRC]

[INDEX]
[FEATURE_ID]
[FEATURE_REV]
...
...
...
[CRC]
$
$ awk -f tst.awk file
$

它不產生任何輸出，這與預期的一樣，因為您提供的樣本沒有錯誤可供查找。