A preceding <backslash> character shall be used to escape a literal '{' or '}'. The rule in Parameter Expansion shall be used to determine the matching '}'.` The backquote shall retain its special meaning introducing the other form of command substitution (see Command Substitution). The ...
If the ith character of this environment variable's value is 1, do not consider the ith operand of grep to be an option, even if it appears to be one. A shell can put this variable in the environment for each command it runs, specifying which operands are the results of file name ...
example, the commandgrep -E '{1'searches for the two-character string{1instead of reporting a syntax error in the regular expression. POSIX.2 allows this behavior as an extension, but portable scripts should avoid it. POSIX字符: 为了在不同国家的字符编码中保持一至,POSIX(The Portable Operating...
Skip any command-line file with a name suffix that matches the pattern GLOB, using wildcard matching; a name suffix is either the whole name, or a trailing part that starts with a non-slash character immediately after a slash (/) in the name. A pattern can use *, ?, and [...] a...
grep: character class syntax is[[:space:]],not[:space:] $ grep[[:alnum:]]testfile This is a teststring. New. This is a testString 可以看到,grep [:alnum:] testfile命令执行报错,提示正确的语法格式是把[:space:]再放到一个方括号[]里面。
If the ith character of this environment variable's value is 1, do not consider the ith operand of grep to be an option, even if it appears to be one. A shell can put this variable in the environment for each command it runs, specifying which operands are the results of file name ...
The+character matches an expression one or more times. This is almost like the*meta-character, but with the+character, the expressionmustmatch at least once. The following expression matches the stringfreeplus one or more characters that are not white space characters: ...
{.GNUgrep-Eattempts to support traditional usage by assuming that{is not specialifit would be the startofan invalid interval specification.For example,the command grep-E'{1'searchesforthe two-character string{1insteadofreporting a syntax errorinthe regular expression.POSIX.2allowsthisbehaviorasan ...
{ is not special if it would be the start of an invalid interval specification. For example, the command grep -E '{1' searches for the two-character string {1 instead of reporting a syntax error in the regular expression. POSIX.2 allows this behavior as an extension, but portable ...
Since shell information is stored in the end of the line, we can instruct grep command to look for the specified search pattern only in the end of line. The Meta character$is used to force the grep command to search the specified pattern only in the end of the lines. ...