Chapter 2. Unix Commands

Options

-debug

Run the applet viewer from within the Java debugger, jdb.

-encoding name

Specify the input HTML file encoding.

-J opt

Pass opt on to the java command. opt should not contain spaces; use multiple -J options if necessary.

Options

-c

Sort the queue according to the time the at command was given.

-n

Print only the total number of jobs in queue.

Options

-a

Remove all jobs belonging to the current user. (A privileged user can remove all jobs.)

-f

Remove jobs unconditionally, suppressing all information regarding removal.

-i

Prompt for y (remove the job) or n (do not remove).

pattern { procedure }

Options

-c

Do not invoke dc; compile only. (Since bc is a preprocessor for dc, bc normally invokes dc.)

-l

Make available functions from the math library.

bc is a language (and compiler) whose syntax resembles that of C. bc consists of identifiers, keywords, and symbols, which are briefly described here. Examples follow at the end.

Identifiers

An identifier is a single character, consisting of the lowercase letters a–z. Identifiers are used as names for variables, arrays, and functions. Within the same program you may name a variable, an array, and a function using the same letter. The following identifiers would not conflict:

Input/Output Keywords

ibase, obase, and scale each store a value. Typing them on a line by themselves displays their current value. More commonly, you would change their values through assignment. Letters A–F are treated as digits whose values are 10–15.

ibase = n

Numbers that are input (e.g., typed) are read as base n (default is 10).

obase = n

Numbers displayed are in base n (default is 10). Note: once ibase has been changed from 10, use digit “A” to restore ibase or obase to decimal.

scale = n

Display computations using n decimal places (default is 0, meaning that results are truncated to integers). scale is normally used only for base-10 computations.

Statement Keywords

A semicolon or a newline separates one statement from another. Curly braces are needed only when grouping multiple statements.

if (rel-expr) {statements}

Do one or more statements if relational expression rel-expr is true; for example:

if (x == y) i = i + 1

while (rel-expr) {statements}

Repeat one or more statements while rel-expr is true; for example:

while (i > 0) {p = p*n; q = a/b; i = i-1}

for (expr1; rel-expr; expr2) {statements}

Similar to while; for example, to print the first 10 multiples of 5, you could type:

for (i = 1; i <= 10; i++) i*5

break

Terminate a while or for statement.

quit

Exit bc.

Function Keywords

define j(k) {

Begin the definition of function j having a single argument k. Additional arguments are allowed, separated by commas. Statements follow on successive lines. End with a }.

auto x, y

Set up x and y as variables local to a function definition, initialized to 0 and meaningless outside the function. Must appear first.

return(expr)

Pass the value of expression expr back to the program. Return 0 if (expr) is left off. Used in function definitions.

sqrt(expr)

Compute the square root of expression expr.

length(expr)

Compute how many digits are in expr.

scale(expr)

Same, but count only digits to the right of the decimal point.

Math Library Functions

These are available when bc is invoked with -l. Library functions set scale to 20.

s(angle)

Compute the sine of angle, a constant or expression in radians.

c(angle)

Compute the cosine of angle, a constant or expression in radians.

a(n)

Compute the arctangent of n, returning an angle in radians.

e(expr)

Compute e to the power of expr.

l(expr)

Compute natural log of expr.

j(n, x)

Compute Bessel function of integer order n.

Operators

These consist of operators and other symbols. Operators can be arithmetic, unary, assignment, or relational.

Other Symbols

/* */

Enclose comments.

( )

Control the evaluation of expressions (change precedence). Can also be used around assignment statements to force the result to print.

{ }

Used to group statements.

[ ]

Array index.

"text"

Use as a statement to print text.

Examples

Note that when you type some quantity (a number or expression), it is evaluated and printed, but assignment statements produce no display:

ibase = 8          Octal input

20                 Evaluate this octal number
16                Terminal displays decimal value

obase = 2          Display output in base 2 instead of base 10

20                 Octal input
10000             Terminal now displays binary value

ibase = A          Restore base 10 input

scale = 3          Truncate results to three places

8/7                Evaluate a division
1.001001000       Oops! Forgot to reset output base to 10

obase = 10         Input is decimal now, so "A" isn't needed

8/7
1.142             Terminal displays result (truncated)

The following lines show the use of functions:

define p(r,n){    Function p uses two arguments
  
auto v          v is a local variable
  
v = r^n         r raised to the n power
  
return(v)}      Value returned

scale = 5

x = p(2.5,2)    x = 2.5 ^ 2

x               Print value of x
6.25
length(x)       Number of digits
3
scale(x)        Number of places to right of decimal point
2

When mail notification is turned on, each time you get incoming mail, the bell rings, and the first few lines of each message are displayed.

Examples

cal 12 1999
cal 1999 > year_file

5/4     meeting with design group at 2 pm
may 6   pick up anniversary card on way home

When you run calendar on May 4, the first line is displayed. calendar can be automated by using crontab or at, or by including it in your startup files .profile or .login.

Option

–

Allow a privileged user to invoke calendar for all users, searching each user's login directory for a file named calendar. Entries that match are sent to a user via mail. This feature is intended for use via cron. It is not recommended in networked environments with large user bases.

Options

id

Cancel print request id.

-u user

Cancel request associated with user.

Options

-b

Like -n, but don't number blank lines. Solaris only.

-e

Print a $ to mark the end of each line. Must be used with -v.

-n

Number lines. Solaris only.

-s

Suppress messages about nonexistent files. (Note: On some systems, -s squeezes out extra blank lines.)

-t

Print each tab as ^I and each form feed as ^L. Must be used with -v.

-u

Print output as unbuffered (default is buffered in blocks or screen lines).

-v

Display control characters and other nonprinting characters.

Examples

cat ch1                              Display a file

cat ch1 ch2 ch3 > all                Combine files

cat note5 >> notes                   Append to a file

cat > temp1                          Create file at terminal; end with EOF

cat > temp2 << STOP                  Create file at terminal; end with STOP

Options

-j

Join split lines.

-l length

Split lines longer than length.

-s

Standardize code to style of Kernighan and Ritchie in The C Programming Language.

-V

Print the version of cb on standard error.

Example

cb -l 70 calc.c > calc_new.c

Notes

• Add /usr/ccs/bin to your PATH to use the C compiler and other C Compilation System tools. This command runs the ANSI C compiler; use /usr/bin/cc if you want to run the compiler for pre-ANSI C.

• Solaris 7 does not come with a C compiler. You must purchase one separately from Sun, or download the GNU C Compiler (GCC) from http://www.sunfreeware.com.

• Options for cc vary wildly across Unix systems. We have chosen here to document only those options that are commonly available. You will need to check your local documentation for complete information.

• Usually, cc passes any unrecognized options to the loader, ld.

Options

Example

Compile xpop.c and load it with the X libraries:

cc -o xpop xpop.c -lXaw -lXmu -lXt -lX11

Options

-dn

Stop outlining when nesting level n is reached.

-i_

Include functions whose names begin with _.

-ix

Include external and static data symbols.

-r

Invert the listing; show the callers of each function and sort in lexicographical order by callee.

checknr works best when input is designed for its conventions: \fP always ends a font change, and \s0 always restores a point-size change. checknr knows about the me and ms macros.

Options

-amacros

Add new pairs of macros that come in open/close pairs. The six characters representing the new macros must immediately follow the -a, e.g., -a.PS.PE for the pic macros.

-ccommands

Don't complain that the given commands are undefined. String the command names together, as in -a. Useful if you have your own macro package.

-f

Ignore inline font changes (\f).

-s

Ignore inline point-size changes (\s).

Options

-f

Force error messages to be suppressed.

-h

Change the group on symbolic links. Normally, chgrp acts on the file referenced by a symbolic link, not on the link itself. (This option is not necessarily available on all Unix systems.)

-R

Recursively descend through the directory, including subdirectories and symbolic links, setting the specified group ID as it proceeds.

Options

-f

Suppress error message upon failure to change a file's mode.

-R

Recursively descend directory arguments while setting modes.

Who

Opcode

Permission

Alternatively, specify permissions by a three-digit sequence. The first digit designates owner permission; the second, group permission; and the third, others permission. Permissions are calculated by adding the following octal values:

Note: a fourth digit may precede this sequence. This digit assigns the following modes:

Examples

Add execute-by-user permission to file:

chmod u+x file

Either of the following assigns read-write-execute permission by owner (7), read-execute permission by group (5), and execute-only permission by others (1) to file:

chmod 751 file
chmod u=rwx,g=rx,o=x file

Any one of the following assigns read-only permission to file for everyone:

chmod =r file
chmod 444 file
chmod a-wx,a+r file

Set the user ID, assign read-write-execute permission by owner, and assign read-execute permission by group and others:

chmod 4755 file

Note: some systems accept a period as well as the colon for separating newowner and newgroup. The colon is mandated by POSIX; the period is accepted for compatibility with older BSD systems.

Options

-f

Force error messages to be suppressed.

-h

Change the owner on symbolic links. Normally, chown acts on the file referenced by a symbolic link, not on the link itself. (This option is not necessarily available on all Unix systems.)

-R

Recursively descend through the directory, including subdirectories and symbolic links, resetting the ownership ID.

sum count filename

Here, sum is the CRC, count is the number of bytes in the file, and filename is the file's name. The name is omitted if standard input is used.

Options

-b

Ignore backspace characters; helpful when printing manpages.

-f

Process half-line vertical motions, but not reverse line motion. (Normally, half-line input motion is displayed on the next full line.)

-p

Print unknown escape sequences (normally ignored) as regular characters. This option can garble output, so its use is not recommended.

-x

Normally, col saves printing time by converting sequences of spaces to tabs. Use -x to suppress this conversion.

Examples

Run file through tbl and nroff, then capture output on screen by filtering through col and more:

tbl file | nroff | col | more

Save manpage output in file.print, stripping out backspaces (which would otherwise appear as ^H):

man file | col -b > file.print

Options

–

Read the standard input.

-1

Suppress printing of Column 1.

-2

Suppress printing of Column 2.

-3

Suppress printing of Column 3.

-12

Print only lines in Column 3 (lines common to file1 and file2).

-13

Print only lines in Column 2 (lines unique to file2).

-23

Print only lines in Column 1 (lines unique to file1).

Example

Compare two lists of top-10 movies and display items that appear in both lists:

comm -12 shalit_top10 maltin_top10

With a filename of –, or with no files, compress reads standard input.

Note: Unisys claims a patent on the algorithm used by compress. Today, gzip is generally preferred for file compression.

Options

-bn

Limit the number of bits in coding to n; n is 9–16, and 16 is the default. A lower n produces a larger, less densely compressed file.

-c

Write to the standard output (do not change files).

-f

Compress unconditionally; i.e., do not prompt before overwriting files. Also, compress files even if the resulting file would actually be larger.

-v

Print the resulting percentage of reduction for files.

Options

-i

Prompt for confirmation (y for yes) before overwriting an existing file.

-p

Preserve the modification time and permission modes for the copied file. (Normally cp supplies the permissions of the invoking user.)

-r

Recursively copy a directory, its files, and its subdirectories to a destination directory, duplicating the tree structure. (This option is used with the second command-line format when at least one of the source file arguments is a directory.) Bear in mind that both symbolic and hard links are copied as real files; the linking structure of the original tree is not preserved.

Example

Copy two files to their parent directory (keep the same names):

cp outline memo ..

A crontab file is a list of commands, one per line, that will execute automatically at a given time. Numbers are supplied before each command to specify the execution time. The numbers appear in five fields, as follows:

Minute		0-59
Hour		0-23
Day of month	1-31
Month		1-12
Day of week	0-6, with 0 = Sunday

Use a comma between multiple values, a hyphen to indicate a range, and an asterisk to indicate all possible values. For example, assuming the crontab entries below:

59 3 * * 5	find / -print | backup_program
0 0 1,15 * *	echo "Timesheets due" | mail user

The first command backs up the system files every Friday at 3:59 a.m., and the second command mails a reminder on the 1st and 15th of each month.

Options

-e

Edit the user's current crontab file (or create one).

-l

List the user's file in the crontab directory.

-r

Delete the user's file in the crontab directory.

Options

-b

Build the symbol cross reference only.

-c

Create output in ASCII (don't compress data).

-C

Ignore uppercase/lowercase differences in searches.

-d

Don't update the cross reference.

-e

Don't show the ^E prompt between files.

-f out

Name the cross-reference file out instead of cscope.out.

-i in

Check source files whose names are listed in in rather than in cscope.files.

-I dir

Search for include files in dir before searching the default (/usr/include). cscope searches the current directory, then dir, then the default.

-l

Run in line mode; useful from within a screen editor.

-L

Use with -n pat to do a single search.

-p n

Show the last n parts of the filename path. Default is 1 (filename); use 0 to suppress the filename.

-P path

Use with -d to prepend path to filenames in existing cross reference. This lets you run cscope without changing to the directory where the cross reference was built.

-s dir

Look for source files in directory dir instead of in current directory.

-T

Match only the first eight characters of C symbols.

-u

Build cross reference unconditionally (assume all files changed).

-U

Ignore file timestamps (assume no files changed).

-V

Print the cscope version on first line of screen.

-n pat

Go to field n of input (starting at 0), then find pat.

name	file	context

where name is the function or macro name, file is the source file in which name is defined, and context is a search pattern that shows the line of code containing name. After the list of tags is created, you can invoke vi on any file and type:

:set tags=tagsfile
:tag name

This switches the vi editor to the source file associated with the name listed in tagsfile (which you specify with -f).

Options

-a

Append tag output to existing list of tags.

-B

context uses backward search patterns.

-ftagsfile

Place output in tagsfile (default is tags).

-F

context uses forward search patterns (default).

-t

Include C typedef s as tags.

-u

Update tags file to reflect new locations of functions (e.g., when functions are moved to a different source file). Old tags are deleted; new tags are appended.

-v

Produce a listing (index) of each function, source file, and page number (1 page = 64 lines). -v is intended to create a file for use with vgrind.

-w

Suppress warning messages.

-x

Produce a listing of each function, its line number, source file, and context.

Examples

Store tags in Taglist for all C programs:

ctags -f Taglist *.c

Update tags and store in Newlist:

ctags -u -f Newlist *.c

Options

-e

Print variables as floating point.

-f functions

Trace only the specified functions.

-l n

Follow a statement loop n times (default is 20).

-o

Print variables in octal.

-p s

Print trace output via function s (default is printf).

-P

Run the C preprocessor before tracing.

-Qc

Print information about ctrace in output (if c = y) or suppress information (if c = n, the default).

-rfile

Change the trace function package to file (default is runtime.c).

-s

Suppress certain redundant code.

-tn

Trace n variables per statement (default is 10; maximum is 20).

-u

Print variables as unsigned.

-v functions

Do not trace the specified functions.

-V

Print version information on standard error.

-x

Print variables as floating point.

Options

-c

Report on all files in a single table.

-C

Don't execute the second pass of cxref; save output from first pass in .cx files. (Like -c in lint and cc.)

-d

Simplify report by omitting print declarations.

-F

Print files using full pathname, not just the filename.

-l

Don't print local variables.

-L[n]

Limit the LINE field to n columns (default is 5).

-o file

Send output to file.

-s

Silent mode; don't print input filenames.

-t

Format for 80-column listing.

-V

Print version information on standard error.

-w[n]

Format for maximum width of n columns (default is 80; n must be more than 50).

-Wn1,n2,n3,n4

Set the width of each (or any) column to n1, n2, n3, or n4 (respective defaults are 15, 13, 15, and 20). Column headings are NAME, FILE, FUNCTION, and LINE, respectively.

Format

The actual formatting is done by the strftime(3) library routine. On Solaris, the country-specific formats depend on the setting of the LC_CTYPE, LC_TIME, LC_MESSAGES, and NLSPATH environment variables.

Options

-a s.f

(Privileged user only.) Gradually adjust the system clock until it drifts s seconds away from what it thinks is the “current” time. (This allows continuous micro-adjustment of the clock while the system is running.) f is the fraction of seconds by which time drifts. By default, the clock speeds up; precede s by a -- to slow down.

-u

Display or set the time using Greenwich Mean Time (UTC) .

Strings for Setting the Date

A privileged user can set the date by supplying a numeric string. string consists of time, day, and year concatenated in one of three ways: time or [day]time or [day]time[year]. Note: don't type the brackets.

time

A two-digit hour and two-digit minute (HHMM); HH uses 24-hour format.

day

A two-digit month and two-digit day of month (mmdd); default is current day and month.

year

The year specified as either the full four digits or just the last two digits; default is current year.

Examples

Set the date to July 1 (0701), 4 a.m. (0400), 1999 (99):

date 0701040099

The command:

date +"Hello%t Date is %D %n%t Time is %T"

produces a formatted date as follows:

Hello	Date is 05/09/93
	Time is 17:53:39

Options

bs=n

Set input and output block size to n bytes; this option supersedes ibs and obs.

cbs=n

Set the size of the conversion buffer (logical record length) to n bytes. Use only if the conversion flag is ascii, asciib, ebcdic, ebcdicb, ibm, ibmb, block, or unblock.

conv=flags

Convert the input according to one or more (comma-separated) flags listed below. The first six flags are mutually exclusive. The next two are mutually exclusive with each other, as are the following two.

ascii	EBCDIC to ASCII.
asciib	EBCDIC to ASCII, using BSD-compatible conversions. Solaris only.
ebcdic	ASCII to EBCDIC.
ebcdicb	ASCII to EBCDIC, using BSD-compatible conversions. Solaris only.
ibm	ASCII to EBCDIC with IBM conventions.
ibmb	ASCII to EBCDIC with IBM conventions, using BSD-compatible conversions. Solaris only.
block	Variable-length records (i.e., those terminated by a newline) to fixed-length records.
unblock	Fixed-length records to variable-length.
lcase	Uppercase to lowercase.
ucase	Lowercase to uppercase.
noerror	Continue processing when errors occur (up to five in a row).
notrunc	Do not truncate the output file. This preserves blocks in the output file that this invocation of dd did not write. Solaris only.
swab	Swap all pairs of bytes.
sync	Pad input blocks to ibs.

count=n

Copy only n input blocks.

files=n

Copy n input files (e.g., from magnetic tape), then quit.

ibs=n

Set input block size to n bytes (default is 512).

if=file

Read input from file (default is standard input).

obs=n

Set output block size to n bytes (default is 512).

of=file

Write output to file (default is standard output).

iseek=n

Seek n blocks from start of input file (like skip but more efficient for disk file input).

oseek=n

Seek n blocks from start of output file.

seek=n

Same as oseek (retained for compatibility).

skip=n

Skip n input blocks; useful with magnetic tape.

You can multiply size values (n) by a factor of 1024, 512, or 2 by appending the letters k, b, or w, respectively. You can use the letter x as a multiplication operator between two numbers.

Examples

Convert an input file to all lowercase:

dd if=caps_file of=small_file conv=lcase

Retrieve variable-length data; write it as fixed-length to out:

data_retrieval_cmd | dd of=out conv=sync,block

Options

Options

-a

Provide information about all filesystems, even ones usually marked in /etc/mnttab to be ignored. Solaris only.

-b

Print only the number of free kilobytes.

-e

Print only the number of free files.

-F type

Report on an unmounted filesystem specified by type. Available types can be seen in the file /etc/vfstab.

-g

Print the whole statvfs structure (overriding other print options).

-i

/usr/ucb/df only. Show the number of used and available inodes in a format similar to df -k.

-k

Print allocation in kilobytes (typically used without other options). This option produces output in the format traditionally used by the BSD version of df.

-l

Report only on local filesystems.

-n

Print only the filesystem type name; with no other arguments, -n lists the types for all mounted filesystems.

-o suboptions

Supply a comma-separated list of type-specific suboptions.

-t

Report total allocated space as well as free space.

-V

Echo command line but do not execute command.

Options

-e

Create an ed script to incorporate into file1 all differences between file2 and file3.

-E

Same as -e, but mark with angle brackets any lines that differ between all three files.

-x

Create an ed script to incorporate into file1 all differences between all three files.

-X

Same as -x, but mark with angle brackets any lines that differ between all three files.

-3

Create an ed script to incorporate into file1 differences between file1 and file3.

Example

To run diffmk on multiple files, it's convenient to set up directories in which to keep the old and new versions of your files, and to create a directory in which to store the marked files:

$ mkdir OLD NEW CHANGED

Move your old files to OLD and your new files to NEW. Then use this rudimentary Bourne shell script:

$ cat do.mark
for file
do
   echo "Running diffmk on $file ..."
   diffmk ../OLD/$file $file ../CHANGED/$file
done

You must run the script in the directory of new files:

$ cd NEW
$ do.mark Ch*

Times-Bold	times/bold
Times-Italic	times/italic
Times-Roman	times/roman

Filenames that begin with a slash are used verbatim. Otherwise, they are taken to be relative to the host font directory.

Options

-

Read the standard input.

-f

Search the entire PostScript file instead of just the header comments. Header comments such as %%DocumentFonts: (atend) redirect download to the end of the file. Use this option when such comments aren't present.

-H fontdir

Use fontdir as the directory in which font-definition files are searched (default is /usr/lib/lp/postscript).

-m table

Use map table specified by file table. A leading / in table indicates an absolute pathname; otherwise (as in the previous option), the filename is appended to the fontdir specified by -H. Without -H, the default is /usr/lib/lp/postscript.

-p printer

Normally, download loads fonts that reside on the host machine. With this option, download first checks for fonts that reside on printer (by looking at /etc/lp/printers/printer/residentfonts).

Options

-

Read the standard input.

-c n

Print n copies of each page (default is 1).

-e 0 | 1 | 2

Set text encoding to 0 (default), 1, or 2. Higher encoding reduces the output size and speeds printing, but may be less reliable.

-F dir

Set the font directory to dir (default is /usr/lib/font).

-H dir

Set the host-resident font directory to dir. Files there must describe PostScript fonts and have filenames corresponding to a two-character troff font.

-L file

Set the PostScript prologue to file (default is /usr/lib/postscript/dpost.ps, /usr/lib/lp/postscript/dpost.ps on Solaris).

-m scale

Increase (multiply) the size of logical pages by factor scale (default is 1.0).

-n n

Print n logical pages on each sheet of output (default is 1).

-o list

Print only pages contained in comma-separated list. A page range is specified by n-m.

-O

Omit PostScript pictures from output. Useful when running in a networked environment.

-p layout

Specify layout to be either portrait (long side is vertical; also the default) or landscape (long side is horizontal). layout can be abbreviated to p or l.

-T device

Use device to best describe available PostScript fonts. Default is post, with dpost reading binary files in /usr/lib/font/devpost. Use of -T is discouraged; usually the system PostScript fonts are best, if they are available.

-w n

Draw troff graphics (e.g., pic, tbl) using lines that are n points thick (default is 0.3).

-x n

Offset the x-coordinate of the origin n inches to the right (if n is positive).

-y n

Offset the y-coordinate of the origin n inches down (if n is positive). Default origin is the upper-left corner of the page.

Example

pic file | tbl | eqn | troff -ms -Tpost | dpost -c2 | lp

Options

-a

Print usage for all files, not just subdirectories.

-d

Do not cross filesystem boundaries. Solaris only.

-k

Print information in units of kilobytes.

-L

For symbolic links, process the file or directory to which the link refers, not the link itself. Solaris only.

-o

Do not add child-directory statistics to the parent directory's total. No effect if -s is also used. Solaris only.

-r

Print a “cannot open” message if a file or directory is inaccessible.

-s

Print only the grand total for each named directory.

Options

-C

Same as -x, but assume file began in encrypted form.

-p string

Set string as the prompt for commands (default is *). The P command turns the prompt display on and off.

-s

Suppress character counts, diagnostics, and the ! prompt for shell commands. Earlier versions of ed used plain -; this is still accepted.

-x

Supply a key to encrypt or decrypt file using crypt.

With volume management available, eject unmounts any filesystems mounted on the named media. In this case, it also displays a pop-up dialog if a window system is running. Without volume management, it simply sends an “eject” command to the given device.

Options

-d

Print the name of the default device to be ejected.

-f

When volume management is not in effect, force the eject, even if the device is busy.

-n

Display the list of nicknames and their corresponding real devices.

-p

Do not use a windowing pop-up dialog.

-q

Query to see if the device has media. Use the exit status to determine the answer.

Options

-c

Print section headers.

-d

Print the .dynamic section.

-e

Print the ELF header.

-i

Print the .interp section.

-G

Print the .got section.

-h

Print the .hash section.

-n

Print the .note section.

-N name

Qualify an option with the specific name name (e.g., to choose a specific symbol table with -s).

-p

Print program headers.

-r

Print the relocation sections.

-s

Print the symbol table sections.

-v

Print the version sections.

-w file

Write the specified section to file.

Options

-

Ignore current environment entirely.

-i

Same as -. Solaris only.

cc -O -c  files 2>&1 | error

Options

-n

Do not edit any files; print errors on standard output.

-q

Query. error prompts for a y or n response before inserting error messages into a file.

-s

Print statistics about the different kinds of errors.

-v

After inserting error messages into the source files, run vi on the files.

-t list

Only process files whose suffixes appear in list. Suffixes are dot-separated, and wildcards are allowed, but should be quoted to prevent interpretation by the shell.

expr is typically used in shell scripts to perform simple mathematics, such as addition or subtraction. It is made obsolete in the Korn shell by that program's built-in arithmetic capabilities.

Arithmetic Operators

Use the following operators to produce mathematical expressions whose results are printed:

Addition and subtraction are evaluated last, unless they are grouped inside parentheses. The symbols *, (, and ) have meaning to the shell, so they must be escaped (preceded by a backslash or enclosed in single or double quotes).

Relational Operators

Use relational operators to compare two arguments. Arguments can also be words, in which case comparisons assume a < z and A < Z. If the comparison statement is true, the result is 1; if false, the result is 0. Symbols < and > must be escaped.

Logical Operators

Use logical operators to compare two arguments. Depending on the values, the result can be arg1 (or some portion of it), arg2, or 0. Symbols | and & must be escaped.

|

Logical OR; if arg1 has a nonzero (and nonnull) value, the result is arg1; otherwise, the result is arg2.

&

Logical AND; if both arg1 and arg2 have a nonzero (and nonnull) value, the result is arg1; otherwise, the result is 0.

:

Similar to grep; arg2 is a pattern to search for in arg1. arg2 must be a regular expression in this case. If the arg2 pattern is enclosed in \( \), the result is the portion of arg1 that matches; otherwise, the result is simply the number of characters that match. By default, a pattern match always applies to the beginning of the first argument (the search string implicitly begins with a ^). To match other parts of the string, start the search string with .*.

Examples

Division happens first; result is 10:

expr 5 + 10 / 2

Addition happens first; result is 7 (truncated from 7.5):

expr \( 5 + 10 \) / 2

Add 1 to variable i; this is how variables are incremented in shell scripts:

i=`expr $i + 1`

Print 1 (true) if variable a is the string “hello”:

expr $a = hello

Print 1 (true) if variable b plus 5 equals 10 or more:

expr $b + 5 \>= 10

In the following examples, variable p is the string "version.100". This command prints the number of characters in p:

expr $p : '.*'        Result is 11

Match all characters and print them:

expr $p : '\(.*\)'    Result is "version.100"

Print the number of lowercase letters at the beginning of p:

expr $p : '[a-z]*'     Result is 7

Match the lowercase letters at the beginning of p:

expr $p : '\([a-z]*\)'  Result is "version"

Truncate $x if it contains five or more characters; if not, just print $x. (Logical OR uses the second argument when the first one is 0 or null; i.e., when the match fails.) Double-quoting is a good idea, in case $x contains whitespace characters.

expr "$x" : '\(.....\)' \| "$x"

In a shell script, rename files to their first five letters:

mv "$x" `expr "$x" : '\(.....\)' \| "$x"`

(To avoid overwriting files with similar names, use mv -i.)

Typical use involves three steps:

1. Specify -e and the C source file, and redirect the output to a file. This creates a database of text strings and identifying information.

2. Edit this database by adding information that was previously returned by the mkmsgs command.

3. Specify -r and the C source file, using the edited database as input. This replaces hardcoded text strings with calls to gettxt. gettxt lets you access translated versions of text strings. (The strings reside in a directory specified by environment variable LC_MESSAGES.)

Options

-d

Use with -r to give the gettxt call a second argument, the original text string. This string is printed as the fallback in case the gettxt call fails.

-e

Extract text strings from file. (-e is not used with other options.) The information appears in this format:

file:line:field:msg_file:msg_num:string

-r

Replace strings in the source file with calls to gettxt.

Example

Assume a C source file named proverbs.c:

main() {
     printf("Haste makes waste\n"); 
     printf("A stitch in time\n"); 
}

1. First issue the command:

   exstr -e proverbs.c > proverb.list

   proverb.list might look something like this:

   proverbs.c:3:8:::Haste makes waste\n 
   proverbs.c:4:8:::A stitch in time\n

2. Run mkmsgs to create a message file (e.g., prov.US) that can be read by the gettxt call. If the two previous proverb strings are listed ninth and tenth in prov.US, you would edit proverb.list as follows:

   proverbs.c:3:8:prov.US:9:Haste makes waste\n 
   proverbs.c:4:8:prov.US:10:A stitch in time\n

3. Finally, specify -r to insert gettxt calls:

   exstr -rd proverbs.c < proverb.list > Prov.c

   The internationalized version of your program, Prov.c, now looks like this:

   extern char *gettxt();
   main() {
     printf(gettxt("prov.US:9",
         "Haste makes waste\n")); 
     printf(gettxt("prov.US:10",
         "A stitch in time\n")); 
   }

Options

-b label

Apply the label to the media. SunOS labels may be up to eight characters; DOS labels may be up to eleven uppercase characters.

-B file

Install bootloader in file on an MS-DOS diskette. Can only be used with -d or -t dos.

-D

Format a 720KB (3.5 inch) or 360KB (5.25 inch) double-density diskette (same as -l or -L). Use on high- or extended-density drives.

-e

Eject floppy disk when done.

-E

Format a 2.88MB (3.5 inch) extended-density diskette.

-f

Force. Do not prompt for confirmation before formatting.

-H

Format a 1.44MB (3.5 inch) or 1.2MB (5.25 inch) high-density diskette. Use on extended-density drive.

-M

Use a 1.2MB (3.5 inch) medium-density format on a high-density diskette. Use only with the -t nec option. Identical to -m.

-U

Unmount any filesystems on the media, and then format.

-q

Quiet mode. Don't print status messages.

-v

Verify each block on the media after formatting.

-x

Don't format, just write a SunOS label or MS-DOS filesystem.

-t dos

Install an MS-DOS filesystem and boot sector formatting. Same as DOS format or -d.

-t nec

Install an NEC-DOS filesystem and boot sector after formatting. Use only with -M.

Compatibility Options

These options are for compatibility with previous versions of fdformat. Their use is discouraged.

-d

Same as -t dos.

-l

Same as -D or -L.

-L

Same as -l or -D.

-m

Same as -M.

Options

-c

Check the format of the magic file (files argument is invalid with -c).

-flist

Run file on the filenames in list.

-h

Do not follow symbolic links.

-mfile

Use file as the magic file instead of /etc/magic.

Many file types are understood. Output lists each filename, followed by a brief classification such as:

ascii text
c program text
c-shell commands
data
empty
iAPX 386 executable
directory
[nt]roff, tbl, or eqn input text
shell commands
symbolic link to ../usr/etc/arp

Example

List all files that are deemed to be nroff/troff input:

file * | grep roff

Conditions may be grouped by enclosing them in \( \) (escaped parentheses), negated with ! (use \! in the C shell), given as alternatives by separating them with -o, or repeated (adding restrictions to the match; usually only for -name, -type, and -perm).

Options

-b

Omit user's home directory and shell from display.

-f

Used with -s to omit heading that normally displays in short format.

-h

Omit .project file from display.

-i

Show “idle” format, a terse format (like -s).

-l

Force long format (default).

-m

users must match usernames exactly, instead of also searching for a match of first or last names.

-p

Omit .plan file from display.

-q

Show “quick” format, the tersest of all (requires an exact match of username).

-s

Show short format.

-w

Used with -s to omit user's full name that normally displays in short format.

!}fmt

Options

-c

Don't adjust the first two lines; align subsequent lines with the second line. Useful for paragraphs that begin with a hanging tag.

-s

Split long lines but leave short lines alone. Useful for preserving partial lines of code.

-w n

Create lines no longer than n columns wide. Default is 72. (Can also be invoked as -n for compatibility with BSD.)

Options

-d

Enable debugging.

-g

Disable filename expansion (globbing).

-i

Turn off interactive prompting.

-n

No auto-login upon initial connection.

-v

Verbose on. Show all responses from remote server.

Option

-o file

Create core file named file.process_id (default is core.process_id).

Options

-a

Print the names and values of all system configuration variables.

-v spec

Use spec to govern the selection of values for configuration variables.

gzip ignores symbolic links. The original file's name, permissions, and modification time are stored in the compressed file, and restored when the file is uncompressed. gzip is capable of uncompressing files that were compressed with compress, pack, or the BSD compact. Default options may be placed in the environment variable GZIP.

gunzip is equivalent to gzip -d. It is typically a hard link to the gzip command. gzcat and zcat are equivalent to gunzip -c, and are also often hard links to gzip.

Note: while not distributed with SVR4 or Solaris, gzip is the de facto standard file compression program for files available over the Internet. Source code can be obtained from the Free Software Foundation (http://www.gnu.org). Precompiled binaries for Solaris can be obtained from http://www.sunfreeware.com. gzip also has its own web site: see http://www.gzip.org.

Options

Like most GNU programs, gzip has both short and long versions of its command-line options:

-a, --ascii

ASCII text mode: convert end-of-lines using local conventions. Not supported on all systems.

-c, --stdout, --to-stdout

Write output on standard output; keep original files unchanged. Individual input files are compressed separately; for better compression, concatenate all the input files first.

-d, --decompress, --uncompress

Decompress.

-f, --force

Force. The file is compressed or decompressed, even if the target file exists or if the file has multiple links.

-h, --help

Display a help screen and exit.

-l, --list

List the compressed and uncompressed sizes, the compression ratio, and the original name of the file for each compressed file. With --verbose, also list the compression method, the 32-bit CRC, and the original file's last-modification time. With --quiet, the title and totals lines are not displayed.

-L, --license

Display the gzip license and quit.

-n, --no-name

For gzip, do not save the original filename and modification time in the compressed file. For gunzip, do not restore the original name and modification time; use those of the compressed file (this is the default).

-N, --name

For gzip, save the original filename and modification time in the compressed file (this is the default). For gunzip, restore the original filename and modification time based on the information in the compressed file.

-q, --quiet

Suppress all warnings.

-r, --recursive

Recursively walk the current directory tree and compress (for gunzip, uncompress) all files found.

-S .suf, --suffix .suf

Use .suf as the suffix instead of .gz. A null suffix makes gunzip attempt decompression on all named files, no matter what their suffix.

-t, --test

Check the compressed file integrity.

-v, --verbose

Display the name and percentage reduction for each file compressed or decompressed.

-V, --version

Display the version number and compilation options, and then quit.

-n, --fast, --best

Control the compression method. n is a number between 1 and 9. -1 (same as --fast) gives the fastest, but least compressed method. -9 (same as --best) gives the best compression, but is slower. Values between 1 and 9 vary the tradeoff in compression method. The default compression level is -6, which gives better compression at some expense in speed. In practice, the default is excellent, and you should not need to use these options.

Options

-n

Print the first n lines of the file.

-n n

Print the first n lines of the file. Solaris only.

Examples

Display the first 20 lines of phone_list:

head -20 phone_list

Display the first 10 phone numbers having a 202 area code:

grep '(202)' phone_list | head

Options

-m shmid

Remove shared memory identifier shmid.

-M shmkey

Remove shmid created with key shmkey.

-q msqid

Remove message queue identifier msqid.

-Q msgkey

Remove msqid created with key msgkey.

-s semid

Remove semaphore identifier semid.

-S semkey

Remove semid created with key semkey.

Options

-m

Report on active shared memory segments.

-q

Report on active message queues.

-s

Report on active semaphores.

With the -m, -q, or -s options, only the specified interprocess facility is reported on. Otherwise, information about all three is printed.

-a

Use almost all the print options (short for -bcopt).

-A

Use all of the print options (short for -bciopt). Solaris only.

-b

Report maximum allowed number of message bytes, segment sizes, and number of semaphores.

-c

Report the creator's login name and group.

-Cfile

Read status from file instead of from /dev/kmem.

-i

Report the number of shared-memory attaches to the segment. Solaris only.

-Nlist

Use the argument for the kernel “name list” (the list of functions and variables in the kernel) instead of /stand/unix (Solaris: /dev/ksyms).

-o

Report outstanding usage.

-p

Report process numbers.

-t

Report time information.

Usage is similar to tar, in that the leading – may be omitted from the options.

Options

-c

Create a new or empty archive to standard output.

-f

The second argument, dest, is the archive to process.

-M

Use specified manifest instead of creating a manifest file.

-m

Don't create a manifest file.

-o

Don't compress the files with ZIP compression.

-t

Print a table of contents for the archive on standard output.

-v

Produce verbose output to standard error.

-x[file]

Extract named file, or all files if no file given.