<\/a> <\/h2>\nThe 255 exit status allows a utility being used by xargs<\/i> to tell xargs<\/i> to terminate if it knows no further invocations using the current data stream will succeed. Thus, utility<\/i> should explicitly exit<\/i> with an appropriate value to avoid accidentally returning with 255.<\/p>\n
Note that since input is parsed as lines, characters separate arguments, and , , and double-quote characters are used for quoting, if xargs<\/i> is used to bundle the output of commands like find dir<\/i> \u2212print<\/b> or ls<\/i> into commands to be executed, unexpected results are likely if any filenames contain , , or quoting characters. This can be solved by using find to call a script that converts each file found into a quoted string that is then piped to xargs<\/i>, but in most cases it is preferable just to have find<\/i> do the argument aggregation itself by using \u2212exec<\/b> with a \u2019+\u2019<\/b> terminator instead of \u2019;\u2019<\/b>. Note that the quoting rules used by xargs<\/i> are not the same as in the shell. They were not made consistent here because existing applications depend on the current rules. An easy (but inefficient) method that can be used to transform input consisting of one argument per line into a quoted form that xargs<\/i> interprets correctly is to precede each non- character with a . More efficient alternatives are shown in Example 2 and Example 5 below.<\/p>\nOn implementations with a large value for {ARG_MAX}, xargs<\/i> may produce command lines longer than {LINE_MAX}. For invocation of utilities, this is not a problem. If xargs<\/i> is being used to create a text file, users should explicitly set the maximum command line length with the \u2212s<\/b> option.<\/p>\n
The command<\/i>, env<\/i>, nice<\/i>, nohup<\/i>, time<\/i>, and xargs<\/i> utilities have been specified to use exit code 127 if an error occurs so that applications can distinguish \u2018\u2018failure to find a utility\u2019\u2019 from \u2018\u2018invoked utility exited with an error indication\u2019\u2019. The value 127 was chosen because it is not commonly used for other meanings; most utilities use small values for \u2018\u2018normal error conditions\u2019\u2019 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. Some scripts produce meaningful error messages differentiating the 126 and 127 cases. The distinction between exit codes 126 and 127 is based on KornShell practice that uses 127 when all attempts to exec<\/i> the utility fail with [ENOENT]<\/b>, and uses 126 when any attempt to exec<\/i> the utility fails for any other reason.<\/p>\n\n\n| <\/td>\n | \n 1.<\/p>\n<\/td>\n | <\/td>\n | \n The following command combines the output of the parenthesized commands (minus the characters) onto one line, which is then appended to the file log. It assumes that the expansion of “$0<\/b>$*” does not include any or characters.<\/p>\n<\/td>\n<\/tr>\n<\/table>\n(logname; date; printf “‘%s’n$0 $*”) | xargs -E “” >>log<\/p>\n \n\n| <\/td>\n | \n 2.<\/p>\n<\/td>\n | <\/td>\n | \n The following command invokes | |