Bash特殊变量(Bash Special Variables) $# Number of command-line arguments. 传递给脚本或函数的参数个数。 $_ The underscore variable is set at shell startup and contains the absolute file name of the shell or script being ex
Exported variables. file Filenames. function Names of shell functions. group Group names. helptopic Help topics as allowed by the help built-in command. hostname Hostnames, as found in the file named by $HOSTFILE. job Job names. keyword Shell reserved keywords. runnin...
shell variables and functions marked for export, along with variables exported for the command, passed in the environment (see Environment) 可以看到,bash 会在一个单独的执行环境中执行简单命令,并从父 shell 中继承一些值。 其中,父 shell 里面定义的变量,默认不会被子 shell 继承。 只有经过export命令导出...
How to export a variable; how to set and export a variable; how to list the exported variables. Exported variables are passed to child processes forked by the shell. This can be prevented by launching the subprocess with env -i. Subshells created with parens ( ) have access non-exported ...
git_remotes_set_https_creds_helpers.sh - adds Git credential helpers configuration to the local git repo to use http API tokens dynamically from environment variables if they're set git_repos_pull.sh - pull multiple repos based on a source file mapping list - useful for easily sync'ing lots...
bash: /usr/bin/du: Argument list too long 如果一个脚本设置了环境变量,需要export它,来通知本脚本的环境,这是export 命令的功能,关于export命令,具体见11章.脚本只能对它产生的子进程export变量.一个从命令行被调用的脚本export的变量,将 不能影响调用这个脚本的那个命令行shell的环境.positional...
git_remotes_set_https_creds_helpers.sh - adds Git credential helpers configuration to the local git repo to use http API tokens dynamically from environment variables if they're set git_repos_pull.sh - pull multiple repos based on a source file mapping list - useful for easily sync'ing lots...
auto-export of variables in initial environment command search finds functions before builtins bash return builtin will exit a file sourced with `.' builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t.
This inspection marks local variables as unused, which are not referenced. The message is displayed under these conditions: The variable is declared as local in a function It’s the first declaration of that variable in that function It’s not exported and there are no references to that varia...
auto-export of variables in initial environment command search finds functions before builtins bash return builtin will exit a file sourced with `.' builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t. export -n/-f/-p/name=value, pwd -L/-P, read -e/...