Search results
Results From The WOW.Com Content Network
In computer programming, a usage message or help message is a brief message displayed by a program that utilizes a command-line interface for execution. This message usually consists of the correct command line usage for the program and includes a list of the correct command-line arguments or options acceptable to said program.
As a command-line interface (CLI), Bash operates within a terminal emulator, or text window, where users input commands to execute various tasks. It also supports the execution of commands from files, known as shell scripts, facilitating automation. In keeping with Unix shell conventions, Bash incorporates a rich set of features.
Line 1 specifies a format pattern for input; the READ command in line 2 and the later PRINT command both reference this line. The DO loop executes line 3. The arithmetic IF statement branches to line 4 on a negative value, line 3 on zero, and again line 3 on a positive value.
This is a list of commands from the GNU Core Utilities for Unix environments. These commands can be found on Unix operating systems and most Unix-like operating systems. GNU Core Utilities include basic file, shell and text manipulation utilities. Coreutils includes all of the basic command-line tools that are expected in a POSIX system.
When it has completed its operation for the last file, paste will output a newline character and move on to the next line. paste exits after all streams return end of file. The number of lines in the output stream will equal the number of lines in the input file with the largest number of lines. Missing values are represented by empty strings.
Take for example one line in the ls -l output: drwxr-xr-x 2 root root 0 Jan 1 1970 home POSIX specifies [5] the format of the output for the long format (-l option). In particular, the first field (before the first space) is dubbed the "file mode string", here drwxr-xr-x. Its first character describes the file type, here d (directory).
On operating systems that support the SUS and POSIX standards, ps commonly runs with the options -ef, where "-e" selects every process and "-f" chooses the "full" output format. Another common option on these systems is -l , which specifies the " l ong" output format.
The number of lines printed may be changed with a command line option. The following example shows the first 20 lines of filename: head -n 20 filename. This displays the first 5 lines of all files starting with foo: head -n 5 foo* Most versions [citation needed] allow omitting n and instead directly specifying the number: -5.