使用awk gsub删除mysql2sqlite脚本中的尾部逗号

我找到了一个将mysql转储转换为sqlite可插入代码的脚本， 我试图去掉括号前的逗号。（所以“defaultnull”后面的逗号。我在这里和那里使用awk和gsub。你可以猜到我对regex不是很熟悉

链接到脚本

此时，我在脚本中使用以下行：

#Replace trailing commas
/\,\n\)/ { /\,\n\)/, "\, " }

但这给了我bash中的以下错误

cmd. line:52: /\,\n\)/ { /\,\n\)/, "\, " }
awk: cmd. line:52:                    ^ syntax error
awk: cmd. line:52: warning: escape sequence `\,' treated as plain `,'
/\,\n\)/ { /\,\n\)/, "\, " }
awk: cmd. line:52:                    ^ syntax error
awk: cmd. line:52: warning: escape sequence `\,' treated as plain `,'
sql exported to  stub-testdb.sqlite

这是我的完整脚本，我在其中添加了删除尾随逗号的行

#!/bin/sh

# Converts a mysqldump file into a Sqlite 3 compatible file. It also extracts the MySQL `KEY xxxxx` from the
# CREATE block and create them in separate commands _after_ all the INSERTs.

# Awk is choosen because it's fast and portable. You can use gawk, original awk or even the lightning fast mawk.
# The mysqldump file is traversed only once.

# Usage: $ ./mysql2sqlite mysqldump-opts db-name | sqlite3 database.sqlite
# Example: $ ./mysql2sqlite --no-data -u root -pMySecretPassWord myDbase | sqlite3 database.sqlite

# Thanks to and @artemyk and @gkuenning for their nice tweaks.

mysqldump  --compatible=ansi --skip-extended-insert --compact  "$@" | \

awk '

# Replace PRIMARY KEY if there is AUTO_INCREMENT
BEGIN { RS="/CREATE TABLE /" }
/NOT NULL AUTO_INCREMENT/ {
        gsub( /\n  PRIMARY KEY \(\"[a-z_]+\"\)/, "" )
        print
        next
}
' | \

awk '

BEGIN {
    FS=",$"
    print "PRAGMA synchronous = OFF;"
    print "PRAGMA journal_mode = MEMORY;"
    print "BEGIN TRANSACTION;"
}

# CREATE TRIGGER statements have funny commenting.  Remember we are in trigger.
/^\/\*.*CREATE.*TRIGGER/ {
    gsub( /^.*TRIGGER/, "CREATE TRIGGER" )
    print
    inTrigger = 1
    next
}

# The end of CREATE TRIGGER has a stray comment terminator
/END \*\/;;/ { gsub( /\*\//, "" ); print; inTrigger = 0; next }

# The r    est of triggers just get passed through
inTrigger != 0 { print; next }

# Skip other comments
/^\/\*/ { next }

# Print all `INSERT` lines. The single quotes are protected by another single quote.
/INSERT/ {
    gsub( /\\\047/, "\047\047" )
    gsub(/\\n/, "\n")
    gsub(/\\r/, "\r")
    gsub(/\\"/, "\"")
    gsub(/\\\\/, "\\")
    gsub(/\\\032/, "\032")
    print
    next
}

# Print the `CREATE` line as is and capture the table name.
/^CREATE/ {
    print
    if ( match( $0, /\"[^\"]+/ ) ) tableName = substr( $0, RSTART+1, RLENGTH-1 ) 
}

#Replace AUTO_INCREMENT with AUTOINCREMENT
/int\([0-9]+\) NOT NULL AUTO_INCREMENT/ { gsub( /int\([0-9]+\) NOT NULL AUTO_INCREMENT/, "INTEGER PRIMARY KEY AUTOINCREMENT" ) }

#Replace table and column COMMENT
/ COMMENT '.*'/ { gsub( / COMMENT '.*'/, "" ) }

#Replace trailing commas
/\,\n\)/ { /\,\n\)/, "\, " }

# Replace `FULLTEXT KEY` or any other `XXXXX KEY` except PRIMARY by `KEY`
/^  [^"]+KEY/ && !/^  PRIMARY KEY/ { gsub( /.+KEY/, "  KEY" ) }

# Get rid of field lengths in KEY lines
/ KEY/ { gsub(/\([0-9]+\)/, "") }

# Print all fields definition lines except the `KEY` lines.
/^  / && !/^(  KEY|\);)/ {
    gsub( /AUTO_INCREMENT/, "" )
    gsub( /(CHARACTER SET|character set) [^ ]+ /, "" )
    gsub( /DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP|default current_timestamp on update current_timestamp/, "" )
    gsub( /(COLLATE|collate) [^ ]+ /, "" )
    gsub(/(ENUM|enum)[^)]+\)/, "text ")
    gsub(/(SET|set)\([^)]+\)/, "text ")
    gsub(/UNSIGNED|unsigned/, "")
    if (prev) print prev ","
    prev = $1
}

# `KEY` lines are extracted from the `CREATE` block and stored in array for later print 
# in a separate `CREATE KEY` command. The index name is prefixed by the table name to 
# avoid a sqlite error for duplicate index name.
/^(  KEY|\);)/ {
    if (prev) print prev
    prev=""
    if ($0 == ");"){
        print
    } else {
        if ( match( $0, /\"[^"]+/ ) ) indexName = substr( $0, RSTART+1, RLENGTH-1 ) 
        if ( match( $0, /\([^()]+/ ) ) indexKey = substr( $0, RSTART+1, RLENGTH-1 ) 
        key[tableName]=key[tableName] "CREATE INDEX \"" tableName "_" indexName "\" ON \"" tableName "\" (" indexKey ");\n"
    }
}

# Print all `KEY` creation lines.
END {
    for (table in key) printf key[table]
    print "END TRANSACTION;"
}
'
exit 0

---

将GNU awk用于多字符RS和GESUB（）：

---

这一行在语法上毫无意义，因此出现了错误消息。我无法想象你为什么认为这是有效的语法。

#!/bin/sh

# Converts a mysqldump file into a Sqlite 3 compatible file. It also extracts the MySQL `KEY xxxxx` from the
# CREATE block and create them in separate commands _after_ all the INSERTs.

# Awk is choosen because it's fast and portable. You can use gawk, original awk or even the lightning fast mawk.
# The mysqldump file is traversed only once.

# Usage: $ ./mysql2sqlite mysqldump-opts db-name | sqlite3 database.sqlite
# Example: $ ./mysql2sqlite --no-data -u root -pMySecretPassWord myDbase | sqlite3 database.sqlite

# Thanks to and @artemyk and @gkuenning for their nice tweaks.

mysqldump  --compatible=ansi --skip-extended-insert --compact  "$@" | \

awk '

# Replace PRIMARY KEY if there is AUTO_INCREMENT
BEGIN { RS="/CREATE TABLE /" }
/NOT NULL AUTO_INCREMENT/ {
        gsub( /\n  PRIMARY KEY \(\"[a-z_]+\"\)/, "" )
        print
        next
}
' | \

awk '

BEGIN {
    FS=",$"
    print "PRAGMA synchronous = OFF;"
    print "PRAGMA journal_mode = MEMORY;"
    print "BEGIN TRANSACTION;"
}

# CREATE TRIGGER statements have funny commenting.  Remember we are in trigger.
/^\/\*.*CREATE.*TRIGGER/ {
    gsub( /^.*TRIGGER/, "CREATE TRIGGER" )
    print
    inTrigger = 1
    next
}

# The end of CREATE TRIGGER has a stray comment terminator
/END \*\/;;/ { gsub( /\*\//, "" ); print; inTrigger = 0; next }

# The r    est of triggers just get passed through
inTrigger != 0 { print; next }

# Skip other comments
/^\/\*/ { next }

# Print all `INSERT` lines. The single quotes are protected by another single quote.
/INSERT/ {
    gsub( /\\\047/, "\047\047" )
    gsub(/\\n/, "\n")
    gsub(/\\r/, "\r")
    gsub(/\\"/, "\"")
    gsub(/\\\\/, "\\")
    gsub(/\\\032/, "\032")
    print
    next
}

# Print the `CREATE` line as is and capture the table name.
/^CREATE/ {
    print
    if ( match( $0, /\"[^\"]+/ ) ) tableName = substr( $0, RSTART+1, RLENGTH-1 ) 
}

#Replace AUTO_INCREMENT with AUTOINCREMENT
/int\([0-9]+\) NOT NULL AUTO_INCREMENT/ { gsub( /int\([0-9]+\) NOT NULL AUTO_INCREMENT/, "INTEGER PRIMARY KEY AUTOINCREMENT" ) }

#Replace table and column COMMENT
/ COMMENT '.*'/ { gsub( / COMMENT '.*'/, "" ) }

#Replace trailing commas
/\,\n\)/ { /\,\n\)/, "\, " }

# Replace `FULLTEXT KEY` or any other `XXXXX KEY` except PRIMARY by `KEY`
/^  [^"]+KEY/ && !/^  PRIMARY KEY/ { gsub( /.+KEY/, "  KEY" ) }

# Get rid of field lengths in KEY lines
/ KEY/ { gsub(/\([0-9]+\)/, "") }

# Print all fields definition lines except the `KEY` lines.
/^  / && !/^(  KEY|\);)/ {
    gsub( /AUTO_INCREMENT/, "" )
    gsub( /(CHARACTER SET|character set) [^ ]+ /, "" )
    gsub( /DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP|default current_timestamp on update current_timestamp/, "" )
    gsub( /(COLLATE|collate) [^ ]+ /, "" )
    gsub(/(ENUM|enum)[^)]+\)/, "text ")
    gsub(/(SET|set)\([^)]+\)/, "text ")
    gsub(/UNSIGNED|unsigned/, "")
    if (prev) print prev ","
    prev = $1
}

# `KEY` lines are extracted from the `CREATE` block and stored in array for later print 
# in a separate `CREATE KEY` command. The index name is prefixed by the table name to 
# avoid a sqlite error for duplicate index name.
/^(  KEY|\);)/ {
    if (prev) print prev
    prev=""
    if ($0 == ");"){
        print
    } else {
        if ( match( $0, /\"[^"]+/ ) ) indexName = substr( $0, RSTART+1, RLENGTH-1 ) 
        if ( match( $0, /\([^()]+/ ) ) indexKey = substr( $0, RSTART+1, RLENGTH-1 ) 
        key[tableName]=key[tableName] "CREATE INDEX \"" tableName "_" indexName "\" ON \"" tableName "\" (" indexKey ");\n"
    }
}

# Print all `KEY` creation lines.
END {
    for (table in key) printf key[table]
    print "END TRANSACTION;"
}
'
exit 0

$ gawk -v RS='^$' -v ORS= '{$0=gensub(/,(\s*\))/,"\\1","g")}1' file
CREATE TABLE "table_name" (
"id" INTEGER PRIMARY KEY AUTOINCREMENT,
"name" varchar(100) NOT NULL,
"created_at" datetime NOT NULL,
"deleted_at" datetime DEFAULT NULL
);