Author: Linux Manual

chdir, fchdir – change working directory Synopsis#include <unistd.h> int chdir(const char *path); int fchdir(int fd); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): fchdir(): _XOPEN_SOURCE >= 500     || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L     || /* Glibc up to and including 2.19: */ _BSD_SOURCEDescriptionchdir() changes the current working directory of the calling process to the directory specified in path. fchdir() is identical to chdir(); the…

execve – execute program Synopsis#include <unistd.h> int execve(const char *pathname, char *const argv[], char *const envp[]); Descriptionexecve() executes the program referred to by pathname. This causes the program that is currently being run by the calling process to be replaced with a new program, with newly initialized stack, heap, and (initialized and uninitialized) data segments….

chown – change file owner and group Synopsischown [,OPTION/]… [,OWNER/][,:/[,GROUP/]] ,FILE/… chown [,OPTION/]… ,–reference=RFILE FILE/… DescriptionThis manual page documents the GNU version of chown. chown changes the user and/or group ownership of each given file. If only an owner (a user name or numeric user ID) is given, that user is made the owner of…

ln – make links between files Synopsisln [,OPTION/]… [,-T/] ,TARGET LINK_NAME/ ln [,OPTION/]… ,TARGET/ ln [,OPTION/]… ,TARGET/… ,DIRECTORY/ ln [,OPTION/]… ,-t DIRECTORY TARGET/… DescriptionIn the 1st form, create a link to TARGET with the name LINK_NAME. In the 2nd form, create a link to TARGET in the current directory. In the 3rd and 4th forms,…

du – estimate file space usage Synopsisdu [,OPTION/]… [,FILE/]… du [,OPTION/]… ,–files0-from=F/ DescriptionSummarize disk usage of the set of FILEs, recursively for directories. Mandatory arguments to long options are mandatory for short options too. -0, –null end each output line with NUL, not newline -a, –all write counts for all files, not just directories –apparent-size…

top – display Linux processes Synopsistop –hv|-bcEeHiOSs1 –d secs –n max –u|U user –p pids –o field –w [cols] The traditional switches `-‘ and whitespace are optional. DescriptionThe top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of processes or threads currently…

curl – transfer a URL Synopsiscurl [options / URLs] Descriptioncurl is a tool for transferring data from or to a server. It supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET or TFTP. The command is…

Wget – The non-interactive network downloader. Synopsiswget [option]… [URL]… DescriptionGNU Wget is a free utility for non-interactive download of files from the Web. It supports HTTP, HTTPS, and FTP protocols, as well as retrieval through HTTP proxies. Wget is non-interactive, meaning that it can work in the background, while the user is not logged on….

scp – OpenSSH secure file copy Synopsisscp [-346ABCOpqRrsTv [-c cipher ] ] [-D sftp_server_path ] [-F ssh_config ] [-i identity_file ] [-J destination ] [-l limit ] [-o ssh_option ] [-P port ] [-S program ] source … target Descriptionscp copies files between hosts on a network. It uses ssh(1) for data transfer, and uses…

ssh – OpenSSH remote login client Synopsisssh [-46AaCfGgKkMNnqsTtVvXxYy [-B bind_interface ] ] [-b bind_address ] [-c cipher_spec ] [-D [bind_address : port ] ] [-E log_file ] [-e escape_char ] [-F configfile ] [-I pkcs11 ] [-i identity_file ] [-J destination ] [-L address ] [-l login_name ] [-m mac_spec ] [-O ctl_cmd ] [-o…

tar – an archiving utility SynopsisTraditional usagetar {A|c|d|r|t|u|x}[GnSkUWOmpsMBiajJzZhPlRvwo] [ARG…] UNIX-style usagetar -A [OPTIONS] ARCHIVE ARCHIVE tar -c [-f ARCHIVE] [OPTIONS] [FILE…] tar -d [-f ARCHIVE] [OPTIONS] [FILE…] tar -t [-f ARCHIVE] [OPTIONS] [MEMBER…] tar -r [-f ARCHIVE] [OPTIONS] [FILE…] tar -u [-f ARCHIVE] [OPTIONS] [FILE…] tar -x [-f ARCHIVE] [OPTIONS] [MEMBER…] GNU-style usagetar {–catenate|–concatenate} [OPTIONS]…

tail – output the last part of files Synopsistail [,OPTION/]… [,FILE/]… DescriptionPrint the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Mandatory arguments to long options are mandatory for…

sed – stream editor for filtering and transforming text Synopsissed [OPTION]… {script-only-if-no-other-script} [input-file]… DescriptionSed is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline). While in some ways similar to an editor which permits scripted edits (such as ed), sed…

gawk – pattern scanning and processing language Synopsisgawk [ POSIX or GNU style options ] -f program-file [ — ] file … gawk [ POSIX or GNU style options ] [ — ] program-text file … DescriptionGawk is the GNU Project’s implementation of the AWK programming language. It conforms to the definition of the language…

pipe, pipe2 – create pipe Synopsis#include <unistd.h> /* On Alpha, IA-64, MIPS, SuperH, and SPARC/SPARC64; see NOTES */ struct fd_pair { long fd[2]; }; struct fd_pair pipe(); /* On all other architectures */ int pipe(int pipefd[2]); #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> /* Obtain O_* constant definitions */ #include <unistd.h> int pipe2(int pipefd[2],…

rm – remove files or directories Synopsisrm [,OPTION/]… [,FILE/]… DescriptionThis manual page documents the GNU version of rm. rm removes each specified file. By default, it does not remove directories. If the -I or –interactive=once option is given, and there are more than three files or the -r, -R, or –recursive are given, then rm…

ps – report a snapshot of the current processes. Synopsisps [,options/] Descriptionps displays information about a selection of the active processes. If you want a repetitive update of the selection and the displayed information, use top instead. This version of ps accepts several kinds of options: 1 UNIX options, which may be grouped and must…

less – opposite of more Synopsisless -? less –help less -V less –version less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~] [-b space/] [-h lines/] [-j line/] [-k keyfile/] [-{oO} logfile/] [-p pattern/] [-P prompt/] [-t tag/] [-T tagsfile/] [-x tab/,…] [-y lines/] [-[z] lines/] [-# shift/] [+[+]cmd/] [–] [filename/]… (See the OPTIONS section for alternate option syntax with long option…

mmap, munmap – map or unmap files or devices into memory Synopsis#include <sys/mman.h> void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset); int munmap(void *addr, size_t length);See NOTES for information on feature test macro requirements. Descriptionmmap() creates a new mapping in the virtual address space of the calling process. The starting…

fork – create a child process Synopsis#include <sys/types.h> #include <unistd.h> pid_t fork(void); Descriptionfork() creates a new process by duplicating the calling process. The new process is referred to as the child process. The calling process is referred to as the parent process. The child process and the parent process run in separate memory spaces. At…