jpegoptim Flags

jpegoptim -help
jpegoptim v1.4.4 Copyright (c) 1996-2016, Timo Kokkonen
Usage: jpegoptim [options]

-d, --dest= specify alternative destination directory for
optimized files (default is to overwrite originals)
-f, --force force optimization
-h, --help display this help and exit
-m, --max=
set maximum image quality factor (disables lossless
optimization mode, which is by default on)
Valid quality values: 0 - 100
-n, --noaction don't really optimize files, just print results
-S, --size=
Try to optimize file to given size (disables lossless
optimization mode). Target size is specified either in
kilo bytes (1 - n) or as percentage (1% - 99%)
-T, --threshold= keep old file if the gain is below a threshold (%)
-b, --csv print progress info in CSV format
-o, --overwrite overwrite target file even if it exists (meaningful
only when used with -d, --dest option)
-p, --preserve preserve file timestamps
-P, --preserve-perms
preserve original file permissions by overwriting it
-q, --quiet quiet mode
-t, --totals print totals after processing all files
-v, --verbose enable verbose mode (positively chatty)
-V, --version print program version

-s, --strip-all strip all markers from output file
--strip-none do not strip any markers
--strip-com strip Comment markers from output file
--strip-exif strip Exif markers from output file
--strip-iptc strip IPTC/Photoshop (APP13) markers from output file
--strip-icc strip ICC profile markers from output file
--strip-xmp strip XMP markers markers from output file

--all-normal force all output files to be non-progressive
--all-progressive force all output files to be progressive
--stdout send output to standard output (instead of a file)
--stdin read input from standard input (instead of a file)

Program Documentation is a documentation hosting platform specializing in windows documentation files. By converting “.chm” windows help files into html format, they become viewable and searchable on the web so programming questions can be answered more easily. contains a wide variety of help documentation from late 90s help files from pre-Windows XP computers to the latest Python documentation.

ulimit flags, commands, and help

help ulimit
ulimit: ulimit [-SHacdefilmnpqrstuvx] [limit]
Modify shell resource limits.

Provides control over the resources available to the shell and processes
it creates, on systems that allow such control.

-S use the `soft' resource limit
-H use the `hard' resource limit
-a all current limits are reported
-b the socket buffer size
-c the maximum size of core files created
-d the maximum size of a process's data segment
-e the maximum scheduling priority (`nice')
-f the maximum size of files written by the shell and its children
-i the maximum number of pending signals
-l the maximum size a process may lock into memory
-m the maximum resident set size
-n the maximum number of open file descriptors
-p the pipe buffer size
-q the maximum number of bytes in POSIX message queues
-r the maximum real-time scheduling priority
-s the maximum stack size
-t the maximum amount of cpu time in seconds
-u the maximum number of user processes
-v the size of virtual memory
-x the maximum number of file locks

If LIMIT is given, it is the new value of the specified resource; the
special LIMIT values `soft', `hard', and `unlimited' stand for the
current soft limit, the current hard limit, and no limit, respectively.
Otherwise, the current value of the specified resource is printed. If
no option is given, then -f is assumed.

Values are in 1024-byte increments, except for -t, which is in seconds,
-p, which is in increments of 512 bytes, and -u, which is an unscaled
number of processes.

Exit Status:
Returns success unless an invalid option is supplied or an error occurs.

netstat usage and flags

netstat -help
netstat: illegal option -- h
Usage: netstat [-AaLlnW] [-f address_family | -p protocol]
netstat [-gilns] [-f address_family]
netstat -i | -I interface [-w wait] [-abdgRtS]
netstat -s [-s] [-f address_family | -p protocol] [-w wait]
netstat -i | -I interface -s [-f address_family | -p protocol]
netstat -m [-m]
netstat -r [-Aaln] [-f address_family]
netstat -rs [-s]

gzip flags

gzip -help
Apple gzip 264.50.1
usage: gzip [-123456789acdfhklLNnqrtVv] [-S .suffix] [ [ ...]]
-1 --fast fastest (worst) compression
-2 .. -8 set compression level
-9 --best best (slowest) compression
-c --stdout write to stdout, keep original files
-d --decompress uncompress files
-f --force force overwriting & compress links
-h --help display this help
-k --keep don't delete input files during operation
-l --list list compressed file contents
-N --name save or restore original file name and time stamp
-n --no-name don't save original file name or time stamp
-q --quiet output no warnings
-r --recursive recursively compress files in directories
-S .suf use suffix .suf instead of .gz
--suffix .suf
-t --test test compressed file
-V --version display program version
-v --verbose print extra statistics

wget Help – commands, usage, flags, examples

GNU Wget 1.15, a non-interactive network retriever.
Usage: wget [OPTION]... [URL]...

Mandatory arguments to long options are mandatory for short options too.

-V, --version display the version of Wget and exit.
-h, --help print this help.
-b, --background go to background after startup.
-e, --execute=COMMAND execute a `.wgetrc'-style command.

Logging and input file:
-o, --output-file=FILE log messages to FILE.
-a, --append-output=FILE append messages to FILE.
-d, --debug print lots of debugging information.
-q, --quiet quiet (no output).
-v, --verbose be verbose (this is the default).
-nv, --no-verbose turn off verboseness, without being quiet.
--report-speed=TYPE Output bandwidth as TYPE. TYPE can be bits.
-i, --input-file=FILE download URLs found in local or external FILE.
-F, --force-html treat input file as HTML.
-B, --base=URL resolves HTML input-file links (-i -F)
relative to URL.
--config=FILE Specify config file to use.

-t, --tries=NUMBER set number of retries to NUMBER (0 unlimits).
--retry-connrefused retry even if connection is refused.
-O, --output-document=FILE write documents to FILE.
-nc, --no-clobber skip downloads that would download to
existing files (overwriting them).
-c, --continue resume getting a partially-downloaded file.
--progress=TYPE select progress gauge type.
-N, --timestamping don't re-retrieve files unless newer than
--no-use-server-timestamps don't set the local file's timestamp by
the one on the server.
-S, --server-response print server response.
--spider don't download anything.
-T, --timeout=SECONDS set all timeout values to SECONDS.
--dns-timeout=SECS set the DNS lookup timeout to SECS.
--connect-timeout=SECS set the connect timeout to SECS.
--read-timeout=SECS set the read timeout to SECS.
-w, --wait=SECONDS wait SECONDS between retrievals.
--waitretry=SECONDS wait 1..SECONDS between retries of a retrieval.
--random-wait wait from 0.5*WAIT...1.5*WAIT secs between retrievals.
--no-proxy explicitly turn off proxy.
-Q, --quota=NUMBER set retrieval quota to NUMBER.
--bind-address=ADDRESS bind to ADDRESS (hostname or IP) on local host.
--limit-rate=RATE limit download rate to RATE.
--no-dns-cache disable caching DNS lookups.
--restrict-file-names=OS restrict chars in file names to ones OS allows.
--ignore-case ignore case when matching files/directories.
-4, --inet4-only connect only to IPv4 addresses.
-6, --inet6-only connect only to IPv6 addresses.
--prefer-family=FAMILY connect first to addresses of specified family,
one of IPv6, IPv4, or none.
--user=USER set both ftp and http user to USER.
--password=PASS set both ftp and http password to PASS.
--ask-password prompt for passwords.
--no-iri turn off IRI support.
--local-encoding=ENC use ENC as the local encoding for IRIs.
--remote-encoding=ENC use ENC as the default remote encoding.
--unlink remove file before clobber.

-nd, --no-directories don't create directories.
-x, --force-directories force creation of directories.
-nH, --no-host-directories don't create host directories.
--protocol-directories use protocol name in directories.
-P, --directory-prefix=PREFIX save files to PREFIX/...
--cut-dirs=NUMBER ignore NUMBER remote directory components.

HTTP options:
--http-user=USER set http user to USER.
--http-password=PASS set http password to PASS.
--no-cache disallow server-cached data.
--default-page=NAME Change the default page name (normally
this is `index.html'.).
-E, --adjust-extension save HTML/CSS documents with proper extensions.
--ignore-length ignore `Content-Length' header field.
--header=STRING insert STRING among the headers.
--max-redirect maximum redirections allowed per page.
--proxy-user=USER set USER as proxy username.
--proxy-password=PASS set PASS as proxy password.
--referer=URL include `Referer: URL' header in HTTP request.
--save-headers save the HTTP headers to file.
-U, --user-agent=AGENT identify as AGENT instead of Wget/VERSION.
--no-http-keep-alive disable HTTP keep-alive (persistent connections).
--no-cookies don't use cookies.
--load-cookies=FILE load cookies from FILE before session.
--save-cookies=FILE save cookies to FILE after session.
--keep-session-cookies load and save session (non-permanent) cookies.
--post-data=STRING use the POST method; send STRING as the data.
--post-file=FILE use the POST method; send contents of FILE.
--method=HTTPMethod use method "HTTPMethod" in the header.
--body-data=STRING Send STRING as data. --method MUST be set.
--body-file=FILE Send contents of FILE. --method MUST be set.
--content-disposition honor the Content-Disposition header when
choosing local file names (EXPERIMENTAL).
--content-on-error output the received content on server errors.
--auth-no-challenge send Basic HTTP authentication information
without first waiting for the server's

HTTPS (SSL/TLS) options:
--secure-protocol=PR choose secure protocol, one of auto, SSLv2,
SSLv3, TLSv1 and PFS.
--https-only only follow secure HTTPS links
--no-check-certificate don't validate the server's certificate.
--certificate=FILE client certificate file.
--certificate-type=TYPE client certificate type, PEM or DER.
--private-key=FILE private key file.
--private-key-type=TYPE private key type, PEM or DER.
--ca-certificate=FILE file with the bundle of CA's.
--ca-directory=DIR directory where hash list of CA's is stored.
--random-file=FILE file with random data for seeding the SSL PRNG.
--egd-file=FILE file naming the EGD socket with random data.

FTP options:
--ftp-user=USER set ftp user to USER.
--ftp-password=PASS set ftp password to PASS.
--no-remove-listing don't remove `.listing' files.
--no-glob turn off FTP file name globbing.
--no-passive-ftp disable the "passive" transfer mode.
--preserve-permissions preserve remote file permissions.
--retr-symlinks when recursing, get linked-to files (not dir).

WARC options:
--warc-file=FILENAME save request/response data to a .warc.gz file.
--warc-header=STRING insert STRING into the warcinfo record.
--warc-max-size=NUMBER set maximum size of WARC files to NUMBER.
--warc-cdx write CDX index files.
--warc-dedup=FILENAME do not store records listed in this CDX file.
--no-warc-compression do not compress WARC files with GZIP.
--no-warc-digests do not calculate SHA1 digests.
--no-warc-keep-log do not store the log file in a WARC record.
--warc-tempdir=DIRECTORY location for temporary files created by the
WARC writer.

Recursive download:
-r, --recursive specify recursive download.
-l, --level=NUMBER maximum recursion depth (inf or 0 for infinite).
--delete-after delete files locally after downloading them.
-k, --convert-links make links in downloaded HTML or CSS point to
local files.
--backups=N before writing file X, rotate up to N backup files.
-K, --backup-converted before converting file X, back up as X.orig.
-m, --mirror shortcut for -N -r -l inf --no-remove-listing.
-p, --page-requisites get all images, etc. needed to display HTML page.
--strict-comments turn on strict (SGML) handling of HTML comments.

Recursive accept/reject:
-A, --accept=LIST comma-separated list of accepted extensions.
-R, --reject=LIST comma-separated list of rejected extensions.
--accept-regex=REGEX regex matching accepted URLs.
--reject-regex=REGEX regex matching rejected URLs.
--regex-type=TYPE regex type (posix).
-D, --domains=LIST comma-separated list of accepted domains.
--exclude-domains=LIST comma-separated list of rejected domains.
--follow-ftp follow FTP links from HTML documents.
--follow-tags=LIST comma-separated list of followed HTML tags.
--ignore-tags=LIST comma-separated list of ignored HTML tags.
-H, --span-hosts go to foreign hosts when recursive.
-L, --relative follow relative links only.
-I, --include-directories=LIST list of allowed directories.
--trust-server-names use the name specified by the redirection
url last component.
-X, --exclude-directories=LIST list of excluded directories.
-np, --no-parent don't ascend to the parent directory.

Mail bug reports and suggestions to .

VIM (Vi IMproved) – Usage, Flags, Command Examples

vim Usage

Edit a file: vim test.txt

vim -help

VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Apr 4 2017 18:14:54)

usage: vim [arguments] [file ..] edit specified file(s)
or: vim [arguments] - read text from stdin
or: vim [arguments] -t tag edit file where tag is defined
or: vim [arguments] -q [errorfile] edit file with first error

-- Only file names after this
-v Vi mode (like "vi")
-e Ex mode (like "ex")
-E Improved Ex mode
-s Silent (batch) mode (only for "ex")
-d Diff mode (like "vimdiff")
-y Easy mode (like "evim", modeless)
-R Readonly mode (like "view")
-Z Restricted mode (like "rvim")
-m Modifications (writing files) not allowed
-M Modifications in text not allowed
-b Binary mode
-l Lisp mode
-C Compatible with Vi: 'compatible'
-N Not fully Vi compatible: 'nocompatible'
-V[N][fname] Be verbose [level N] [log messages to fname]
-D Debugging mode
-n No swap file, use memory only
-r List swap files and exit
-r (with file name) Recover crashed session
-L Same as -r
-T Set terminal type to
-u Use instead of any .vimrc
--noplugin Don't load plugin scripts
-p[N] Open N tab pages (default: one for each file)
-o[N] Open N windows (default: one for each file)
-O[N] Like -o but split vertically
+ Start at end of file
+ Start at line
--cmd Execute before loading any vimrc file
-c Execute after loading the first file
-S Source file after loading the first file
-s Read Normal mode commands from file
-w Append all typed commands to file
Write all typed commands to file
-x Edit encrypted files
--startuptime Write startup timing messages to
-i Use instead of .viminfo
-h or --help Print Help (this message) and exit
--version Print version information and exit

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