51

kill [ -s signal | -p ] This syntax in a manual page means: You can use kill -s signal or you can use kill -p, but you can't use both -s and -p at the same time. The pipe (|) stands for (exclusive) or in the documentation, it's not part of the command. When you type foo | bar in your shell, it will attempt to start foo and bar, and pipe the output of ...


43

Overstriking is a method used in nroff (see the Troff paper) to offer more typographical possibilities than plain ASCII would allow: bold text (by overstriking the same character) underlined text (by overstriking _) accents and diacritics (e.g. é produced by overstriking e with ’) and various other symbols, as permitted by the target output device. In ...


38

Options for compgen command are the same as complete, except -p and -r. From compgen man page: compgen compgen [option] [word] Generate possible completion matches for word according to the options, which may be any option accepted by the complete builtin with the exception of -p and -r, and write the matches to the standard output For options [...


34

The manual is out of date with the program. Try ls --help | grep -- ' -1': -1 list one file per line It is one of the last options described if you just do ls --help.


32

I think you're getting tripped on the fact that there is a builtin command to Bash called kill, along with the command kill. $ type -a kill kill is a shell builtin kill is /usr/bin/kill kill is /bin/kill The man page you're reading is referring to the kill command located under /bin. Use the full path to summon it: $ /bin/kill -p sleep 16486 Incidentally ...


31

help is a built-in command in the bash shell (and that shell only) that documents some of the builtin commands and keywords of that shell. That's an internal documentation system of that shell. Other shells have their own documentation system (ksh93 has --help and --man options for its builtins, zsh has a run-help helper that extracts information from ...


30

From man man: -K, --global-apropos Search for text in all manual pages. This is a brute-force search, and is likely to take some time; if you can, you should specify a section to reduce the number of pages that need to be searched. Search terms may be simple strings (the default), or regular expressions if the --regex ...


30

To use your example: /sys/ doesn't contain "real" files, but is entirely provided by the kernel. Do you want all READMEs to become part of the kernel? You probably don't. Documentation is in /usr/share/doc. Which contains normal files on your harddisk. Some documentation about /sys and /proc is in the kernel source, that is in /usr/src/linux/Documentation (...


27

There are too many sources of information to list in this page: The command echo -e uses an extension to render \e as ASCII 27 (octal 33 or "\033"). The portable way to print these uses printf (POSIX). Compare with standard echo (POSIX). Your example can be rewritten as printf "\033[34m Hello\n \033[0m" the standard for the color escapes is ECMA-48 (...


27

The behaviour is a logical result of the documented algorithm for cp -R. See POSIX, step 2f: The files in the directory source_file shall be copied to the directory dest_file, taking the four steps (1 to 4) listed here with the files as source_files. . and .. are directories, respectively the current directory, and the parent directory. Neither are ...


18

You want man 2 open for the C library interface, not man 3 open. It is indeed in manpages-dev (not manpage-dev). man 3 open gives a Perl manual page. # Show the corresponding source groff file man -w 2 open /usr/share/man/man2/open.2.gz # Show which package this file belongs to dpkg -S /usr/share/man/man2/open.2.gz manpages-dev: /usr/share/man/man2/open....


18

Get gcc-doc package In order to be able to fetch this packages with the apt-get install command we need to edit our sources.list file to include both contrib and non-free repositories. For example, here's my /etc/apt/sources.list file: deb http://httpredir.debian.org/debian/ jessie main contrib non-free deb-src http://httpredir.debian.org/debian/ jessie ...


18

The sequence @t{...} is the texinfo markup to typeset a sequence using fixed-width font (see the Fonts section of the texinfo manual for more details and some examples.) It looks like they were trying to write "C++" and have the "++" use a fixed width font (like "++".) Perhaps someone found that yields better results with specific fonts while rendering ...


17

To list active aliases, run: alias To see names of all active functions, run: declare -F To see the names and definitions of all active functions, run: declare -f More The information on aliases is also available is a script-friendly format with: declare -p BASH_ALIASES man bash provides more info on the alias builtin: alias [-p] [name[=value] .....


15

Even though not a direct answer, git blame and git log reveal that this section was introduced in commit 2c41d783 by a committer called hniksic, who turns out to be Hrvoje Niksic. His email address can be found in wget's ChangeLog file (I won't publish it here for the obvious reasons). I'd suggest asking him directly, as he might be the best to give a more ...


15

That confusing snippet was changed in newer versions of GNU grep to: -i, -ignore-case Ignore case distinctions, so that characters that differ only in case match each other. See this commit: http://git.savannah.gnu.org/cgit/grep.git/commit/?id=e1ca01be48cb64e5eaa6b5b29910e7eea1719f91 .BR \-i ", " \-\^\-ignore\-case -Ignore case distinctions in both ...


14

There is no "recipe" to get the meanings of an exit status of a given terminal command. My first attempt would be the manpage: user@host:~# man ls Exit status: 0 if OK, 1 if minor problems (e.g., cannot access subdirectory), 2 if serious trouble (e.g., cannot access command-line argument). Second: Google. See wget ...


14

The manpage sections are described in the manpages themselves. Enter man man in a shell session to see the various sections and general content: 1 Executable programs or shell commands 2 System calls (functions provided by the kernel) 3 Library calls (functions within program libraries) 4 Special files (usually found in /dev) 5 ...


14

A web search for "backspace" and "overstrike" would get better results. The file is a manual page — formatted using nroff. Usually files such as bash.0 are simply generated and discarded. A while back, they were saved, to reduce work for the man program. Rather than /usr/share/man/man1, your manual pages would be read from /usr/share/man/cat1. Read ...


14

Yes, it's man 7 signal which, among other things, includes the following table: Signal Value Action Comment ────────────────────────────────────────────────────────────────────── SIGHUP 1 Term Hangup detected on controlling terminal or death of controlling process SIGINT 2 ...


14

Because Unix and Linux have a decades old tradition of documenting with man pages (and, on GNU systems, info files ...). See man(1), man(7), man-pages(7). BTW, man command and pages are optional (and you won't install them on every Unix system). The file system hierarchy is described in hier(7). It is defined by the Filesystem Hierachy Standard available ...


13

A large amount of TLDP is obsolete. The howtos are usually good, but many of them are seriously out of date and contain advice that is now counterproductive. Check the date of each howto before deciding whether to read and trust it. Even back in the day, howtos were not to be followed blindly. For example, many howtos start with instructions on compiling ...


13

It should be fine to delete files in /usr/share/doc on Debian-based systems. The Debian policy explicitly specifies in section 12.3: Packages must not require the existence of any files in /usr/share/doc/ in order to function. [...] The system administrator should be able to delete files in /usr/share/doc/ without causing any programs to break. ...


12

I think you're looking for man command. Try doing man mkdir and look for what the -p switch does. You can use vim style searching here. Use man man for more info on how to use man command.


12

Exit codes indicates a failure condition when ending a program and they fall between 0 and 255. The shell and its builtins may use especially the values above 125 to indicate specific failure modes, so list of codes can vary between shells and operating systems (e.g. Bash uses the value 128+N as the exit status). See: Bash - 3.7.5 Exit Status or man bash. ...


12

There are a handful of exit codes with reserved special meanings: Exit Code Number Meaning 1 Catchall for general errors 2 Misuse of shell builtins (according to Bash documentation) 126 Command invoked cannot execute 127 "command not found" 128+n Fatal error signal "n" 130 Script terminated by Ctrl-C 255* Exit status out of range ...


12

No, this is an abbreviated way of listing all the possible single-letter options: -a, -A, -b, etc. See the ping manpage for details (for better results, run man ping on your own system — that will show the documentation for the version you have installed).


11

For bash, the primary resource is man bash. For builtins specifically, there is the help builtin. Here is a quote from help printf. In addition to the standard format specifications described in printf(1) and printf(3), printf interprets: %b expand backslash escape sequences in the corresponding argument %q quote the argument in a way ...


11

The Unix Programmers Manual you linked to is probably mostly relevant for Linux also. However, that manual was published in 1979. Things have changed since then in all descendants of the original Unix.


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