-- return value of the last synchronous command. */ case '?': temp = itos(last_command_exit_value); break; 三、bash对于set选项处理位置 对应的,在内核构建的时候,可以看到每次执行命令前都会执行 set -e ,bash手册对于该命令的说明为: -e Exit immediately if a simple command (see Section 3.2....
exit_statusenabledreturn code of last command gitenabledgit branch/remote and repository status newlinedisabledsplits prompt segments across multiple lines read_onlyenabledindicator of read only directory userenabledusername and host (conditional on ssh status) ...
Thefalsecommand always returns the exit status non-zero to indicate failure. ###$?$?is a variable that will return the exit code of the last command you ran. $ true $ echo $? 0 $ false $ echo $? 1 grep Thegrepcommand is a search function. ...
This is just an example to illustrate the purpose ofreadcommand. It can be useful for users who need to ensure that updates are only applied withexplicit confirmation. Of course, you don't have to write a script forsudo apt-get update && sudo apt-get upgradecommand. It is just an one-...
It is the exit code of the command (seeRecipe 4.4). C language programmers will recognize this as the value of the argument supplied to theexit()function; e.g.,exit(4);would return a4. For the shell, an exit code of zero is considered success and a nonzero value means failure....
The ls command has numerous parameters that modify how the results are displayed. Some frequently used parameters used with the ls command include: Used all together, these parameters give the user a much clearer sense of what files and subdirectories are in a directory, when they have last be...
The TEST-COMMAND list is executed, and if its return status is zero, the CONSEQUENT-COMMANDS list is executed. The return status is the exit status of the last command executed, or zero if no condition tested true. Testing and Branching;elif; ...
Get the last value in the array. ${array[@]} Expand all of the array elements. shift Move argument from $2 to $1. function() { content-of-function } Used to define a function. alias Used to list all aliases defined in the current session. alias alias='any command' Used to define...
The second way to run a script is simply to type its name and hit RETURN, just as if you were invoking a built-in command. This, of course, is the more convenient way. This method makes the script look just like any other UNIX command, and in fact several “regular” commands are ...
struct load_command* cmd = (struct load_command*)(data + sizeof(struct mach_header_64)); // iterate through all the segments once to find highest and lowest addresses uint64_t pc = 0; uint64_t low_addr_temp; uint64_t high_addr_temp; ...