diff options
| -rw-r--r-- | doc/coreutils.texi | 30 | ||||
| -rw-r--r-- | src/tr.c | 11 |
2 files changed, 22 insertions, 19 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 88e16503d..9a27cb109 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -297,7 +297,7 @@ Operating on characters * Character sets:: Specifying sets of characters * Translating:: Changing one set of characters to another -* Squeezing:: Squeezing repeats and deleting +* Squeezing and deleting:: Removing characters Directory listing @@ -1609,7 +1609,8 @@ if @option{-b} is in effect. @opindex -s @opindex --squeeze-blank @cindex squeezing empty lines -Suppress repeated adjacent empty lines; output just one empty line +@cindex squeezing blank lines +Suppress repeated adjacent blank lines; output just one empty line instead of several. @item -t @@ -4968,9 +4969,9 @@ may be better suited for output direct to users. @macro ambiguousGroupNote Note that when groups are delimited and the input stream contains -two or more consecutive blank lines, then the output is ambiguous. -To avoid that, filter the input through @samp{tr -s '\\n'} to replace -each sequence of consecutive newlines with a single newline. +blank lines, then the output is ambiguous. +To avoid that, filter the input through @samp{tr -s '\\n'} to +remove blank lines. @end macro @ambiguousGroupNote @@ -6215,7 +6216,7 @@ options. @xref{Common options}. Options must precede operands. @menu * Character sets:: Specifying sets of characters. * Translating:: Changing one set of characters to another. -* Squeezing:: Squeezing repeats and deleting. +* Squeezing and deleting:: Removing characters. @end menu @@ -6438,18 +6439,20 @@ tr -cs '[:alnum:]' '[\n*]' @end example -@node Squeezing +@node Squeezing and deleting @subsection Squeezing repeats and deleting @cindex squeezing repeat characters @cindex deleting characters +@cindex removing characters When given just the @option{--delete} (@option{-d}) option, @command{tr} removes any input characters that are in @var{set1}. -When given just the @option{--squeeze-repeats} (@option{-s}) option, -@command{tr} replaces each input sequence of a repeated character that -is in @var{set1} with a single occurrence of that character. +When given just the @option{--squeeze-repeats} (@option{-s}) option +and not translating, @command{tr} replaces each input sequence of a +repeated character that is in @var{set1} with a single occurrence of +that character. When given both @option{--delete} and @option{--squeeze-repeats}, @command{tr} first performs any deletions using @var{set1}, then squeezes repeats @@ -6480,7 +6483,8 @@ tr -cs '[:alnum:]' '[\n*]' @end example @item -Convert each sequence of repeated newlines to a single newline: +Convert each sequence of repeated newlines to a single newline. +I.e., delete blank lines: @example tr -s '\n' @@ -17831,8 +17835,8 @@ $ tr '[:upper:]' '[:lower:]' < whats.gnu | tr -cd '[:alnum:]_ \n' | @end smallexample This command turns blanks into newlines. The @option{-s} option squeezes -multiple newline characters in the output into just one. This helps us -avoid blank lines. (The @samp{>} is the shell's ``secondary prompt.'' +multiple newline characters in the output into just one, removing +blank lines. (The @samp{>} is the shell's ``secondary prompt.'' This is what the shell prints when it notices you haven't finished typing in all of a command.) @@ -293,9 +293,9 @@ writing to standard output.\n\ \n\ -c, -C, --complement use the complement of SET1\n\ -d, --delete delete characters in SET1, do not translate\n\ - -s, --squeeze-repeats replace each input sequence of a repeated character\n\ - that is listed in SET1 with a single occurrence\n\ - of that character\n\ + -s, --squeeze-repeats replace each sequence of a repeated character\n\ + that is listed in the last specified SET,\n\ + with a single occurrence of that character\n\ -t, --truncate-set1 first truncate SET1 to length of SET2\n\ "), stdout); fputs (HELP_OPTION_DESCRIPTION, stdout); @@ -342,9 +342,8 @@ Translation occurs if -d is not given and both SET1 and SET2 appear.\n\ SET1 by repeating its last character as necessary. Excess characters\n\ of SET2 are ignored. Only [:lower:] and [:upper:] are guaranteed to\n\ expand in ascending order; used in SET2 while translating, they may\n\ -only be used in pairs to specify case conversion. -s uses SET1 if not\n\ -translating nor deleting; else squeezing uses SET2 and occurs after\n\ -translation or deletion.\n\ +only be used in pairs to specify case conversion. -s uses the last\n\ +specified SET, and occurs after translation or deletion.\n\ "), stdout); emit_ancillary_info (PROGRAM_NAME); } |