xargs(1)							   User Commands							  xargs(1)

NAME

       xargs - construct argument lists and invoke utility

SYNOPSIS

       /usr/bin/xargs  [-t]  [-p] [ -e [eofstr]] [-E eofstr] [-I replstr] [ -i [replstr]] [-L number] [ -l [number]] [ -n number [-x]] [-s size] [
       utility [ argument...]]

       /usr/xpg6/bin/xargs [-t] [-p] [ -e [eofstr]] [-E eofstr] [-I replstr] [	-i  [replstr]]	[-L number]  [	-l  [number]]  [  -n number  [-x]]
       [-s size] [ utility [ argument...]]

DESCRIPTION

       The xargs utility constructs a command line consisting of the utility and argument operands specified followed by as many arguments read in
       sequence from standard input as will fit in length and number constraints specified by the options. The xargs utility then invokes the con-
       structed  command line and waits for its completion. This sequence is repeated until an end-of-file condition is detected on standard input
       or an invocation of a constructed command line returns an exit status of 255.

       Arguments in the standard input must be separated by unquoted blank characters, or unescaped blank  characters  or  newline  characters.  A
       string  of  zero or more non-double-quote (") and non-newline characters can be quoted by enclosing them in double-quotes. A string of zero
       or more non-apostrophe (') and non-newline characters can be quoted by enclosing them in apostrophes. Any unquoted character can be escaped
       by  preceding  it  with	a  backslash (). The utility will be executed one or more times until the end-of-file is reached. The results are
       unspecified if the utility named by utility attempts to read from its standard input.

       The generated command line length will be the sum of the size in bytes of the utility name and each argument treated as strings,  including
       a  null	byte terminator for each of these strings. The xargs utility will limit the command line length such that when the command line is
       invoked, the combined argument and environment lists will not exceed {ARG_MAX}-2048 bytes. Within this constraint, if neither  the  -n  nor
       the -s option is specified, the default command line length will be at least {LINE_MAX}.

OPTIONS

       The following options are supported:

       -e[eofstr]      Uses eofstr as the logical end-of-file string. Underscore (_) is assumed for the logical EOF string if neither -e nor -E is
		       used. When the eofstr option-argument is omitted, the logical EOF string capability is disabled and underscores	are  taken
		       literally. The xargs utility reads standard input until either end-of-file or the logical EOF string is encountered.

       -E eofstr       In /usr/bin/args:

		       Specifies  a  logical  end-of-file  string  to replace the default underscore. The xargs utility reads standard input until
		       either end-of-file or the logical EOF string is encountered. The eofstr cannot be a null string.

		       In /usr/xpg6/bin/args:

		       Specifies a logical end-of-file string to replace the default underscore. The xargs  utility  reads  standard  input  until
		       either  end-of-file  or the logical EOF string is encountered. When eofstr is a null string, the logical end-of-file string
		       capability is disabled and underscore characters are taken literally.

       -I replstr      Insert mode. utility is executed for each line from standard input, taking the entire line as a single argument,  inserting
		       it  in  argument  s  for  each occurrence of replstr. A maximum of five arguments in arguments can each contain one or more
		       instances of replstr. Any blank characters at the beginning of each line are ignored.  Constructed  arguments  cannot  grow
		       larger  than  255 bytes. Option -x is forced on. The -I and -i options are mutually exclusive; the last one specified takes
		       effect.

       -i[replstr]     This option is equivalent to -I replstr. The string {} is assumed for replstr if the option-argument is omitted.

       -L number       The utility is executed for each non-empty number lines of arguments from standard input. The last  invocation  of  utility
		       will be with fewer lines of arguments if fewer than number remain. A line is considered to end with the first newline char-
		       acter unless the last character of the line is a blank character; a trailing blank character signals  continuation  to  the
		       next non-empty line, inclusive. The -L, -l, and -n options are mutually exclusive; the last one specified takes effect.

       -l[number]      (The letter ell.) This option is equivalent to -L number. If number is omitted, 1 is assumed. Option -x is forced on.

       -n number       Invokes	utility  using	as  many standard input arguments as possible, up to number (a positive decimal integer) arguments
		       maximum. Fewer arguments will be used if:

			 o  The command line length accumulated exceeds the size specified by the -s option (or  {LINE_MAX}  if  there	is  no	-s
			    option), or

			 o  The last iteration has fewer than number, but not zero, operands remaining.

       -p	       Prompt  mode.   The  user is asked whether to execute utility at each invocation. Trace mode (-t) is turned on to write the
		       command instance to be executed, followed by a prompt to standard error. An affirmative response (specific  to  the  user's
		       locale) read from /dev/tty will execute the command; otherwise, that particular invocation of utility is skipped.

       -s size	       Invokes	utility  using as many standard input arguments as possible yielding a command line length less than size (a posi-
		       tive decimal integer) bytes. Fewer arguments will be used if:

			 o  The total number of arguments exceeds that specified by the -n option, or

			 o  The total number of lines exceeds that specified by the -L option, or

			 o  End of file is encountered on standard input before size bytes are accumulated.

		       Values of size up to at least {LINE_MAX} bytes are supported, provided that the constraints specified  in  DESCRIPTION  are
		       met. It is not considered an error if a value larger than that supported by the implementation or exceeding the constraints
		       specified in DESCRIPTION is given. xargs will use the largest value it supports within the constraints.

       -t	Enables trace mode. Each generated command line will be written to standard error just prior to invocation.

       -x	Terminates if a command line containing number arguments (see the -n option above) or number lines (see the -L option above)  will
		not fit in the implied or specified size (see the -s option above).

OPERANDS

       The following operands are supported:

       utility	       The  name of the utility to be invoked, found by search path using the PATH environment variable. (ee environ(5).) If util-
		       ity is omitted, the default is the echo(1) utility. If the utility operand names any of the special built-in  utilities	in
		       shell_builtins(1), the results are undefined.

       argument        An initial option or operand for the invocation of utility.

USAGE

       The  255  exit  status allows a utility being used by xargs to tell xargs to terminate if it knows no further invocations using the current
       data stream will succeed. Thus, utility should explicitly exit with an appropriate value to avoid accidentally returning with 255.

       Notice that input is parsed as lines. Blank characters separate arguments. If xargs is used to bundle output  of  commands  like  find  dir
       -print  or  ls into commands to be executed, unexpected results are likely if any filenames contain any blank characters or newline charac-
       ters. This can be fixed by using find to call a script that converts each file found into a quoted string that  is  then  piped	to  xargs.
       Notice  that the quoting rules used by xargs are not the same as in the shell. They were not made consistent here because existing applica-
       tions depend on the current rules and the shell syntax is not fully compatible with it. An easy rule that can  be  used	to  transform  any
       string into a quoted form that xargs will interpret correctly is to precede each character in the string with a backslash ().

       On  implementations  with a large value for {ARG_MAX}, xargs may produce command lines longer than {LINE_MAX}. For invocation of utilities,
       this is not a problem. If xargs is being used to create a text file, users should explicitly set the maximum command line length  with  the
       -s option.

       The xargs utility returns exit status 127 if an error occurs so that applications can distinguish "failure to find a utility" from "invoked
       utility exited with an error indication." The value 127 was chosen because it is not commonly used for other meanings; most  utilities  use
       small  values for "normal error conditions" and the values above 128 can be confused with termination due to receipt of a signal. The value
       126 was chosen in a similar manner to indicate that the utility could be found, but not invoked.

EXAMPLES

       Example 1: Using the xargs command

       The following will move all files from directory $1 to directory $2, and echo each move command just before doing it:

       example% ls $1 | xargs -I {} -t mv $1/{} $2/{}

       The following command will combine the output of the parenthesised commands onto one line, which is then written to the end of file log:

       example% (logname; date; printf "%s
" "$0 $*") | xargs >>log

       The following command will invoke diff with successive pairs of arguments originally typed as command line arguments (assuming there are no
       embedded blank characters in the elements of the original argument list):

       example% printf "%s
" "$*" | xargs -n 2 -x diff

       The  user is asked which files in the current directory are to be archived. The files are archived into arch ; a, one at a time, or b, many
       at a time:

       example% ls | xargs -p -L 1 ar -r arch
       ls | xargs -p -L 1 | xargs ar -r arch

       The following will execute with successive pairs of arguments originally typed as command line arguments:

       example% echo $* | xargs -n 2 diff

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables that affect  the	execution  of  xargs:  LANG,  LC_ALL,  LC_COLLATE,
       LC_CTYPE, LC_MESSAGES, and NLSPATH.

       PATH	Determine the location of utility.

EXIT STATUS

       The following exit values are returned:

       0	       All invocations of utility returned exit status 0.

       1-125	       A  command  line  meeting  the  specified  requirements	could  not be assembled, one or more of the invocations of utility
		       returned a non-zero exit status, or some other error occurred.

       126	       The utility specified by utility was found but could not be invoked.

       127	       The utility specified by utility could not be found.

       If a command line meeting the specified requirements cannot be assembled, the utility cannot be invoked, an invocation of  the  utility	is
       terminated  by  a signal, or an invocation of the utility exits with exit status 255, the xargs utility will write a diagnostic message and
       exit without processing any remaining input.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |CSI			     |Enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       echo(1), shell_builtins(1), attributes(5), environ(5), standards(5)

SunOS 5.10							    3 Sep 2003								  xargs(1)