diff options
| -rw-r--r-- | .travis.yml | 2 | ||||
| -rw-r--r-- | programs/lz4.1.md | 27 | ||||
| -rw-r--r-- | programs/lz4cli.c | 5 | ||||
| -rw-r--r-- | tests/Makefile | 2 |
4 files changed, 18 insertions, 18 deletions
diff --git a/.travis.yml b/.travis.yml index 301d294..2065478 100644 --- a/.travis.yml +++ b/.travis.yml @@ -8,7 +8,7 @@ matrix: os: osx compiler: clang script: - - make -C tests test-lz4 MOREFLAGS='-Werror -Wconversion -Wno-sign-conversion' + - make -C tests test-lz4 MOREFLAGS='-Werror -Wconversion -Wno-sign-conversion' | tee # test scenario where `stdout` is not the console - CFLAGS=-m32 make -C tests clean test-lz4-contentSize # Container-based 12.04 LTS Server Edition 64 bit (doesn't support 32-bit includes) diff --git a/programs/lz4.1.md b/programs/lz4.1.md index 10449a0..ffda3ff 100644 --- a/programs/lz4.1.md +++ b/programs/lz4.1.md @@ -31,29 +31,29 @@ The native file format is the `.lz4` format. `lz4` supports a command line syntax similar _but not identical_ to `gzip(1)`. Differences are : - * `lz4` preserves original files * `lz4` compresses a single file by default (see `-m` for multiple files) * `lz4 file1 file2` means : compress file1 _into_ file2 * `lz4 file.lz4` will default to decompression (use `-z` to force compression) + * `lz4` preserves original files * `lz4` shows real-time notification statistics during compression or decompression of a single file (use `-q` to silence them) - * If no destination name is provided, result is sent to `stdout` - _except if stdout is the console_. - * If no destination name is provided, __and__ if `stdout` is the console, - `file` is compressed into `file.lz4`. - * As a consequence of previous rules, note the following example : - `lz4 file | consumer` sends compressed data to `consumer` through `stdout`, - hence it does _not_ create `file.lz4`. - * Another consequence of those rules is that to run `lz4` under `nohup`, - you should provide a destination file: `nohup lz4 file file.lz4`, - because `nohup` writes the specified command's output to a file. + * When no destination is specified, result is sent on implicit output, + which depends on `stdout` status. + When `stdout` _is Not the console_, it becomes the implicit output. + Otherwise, if `stdout` is the console, the implicit output is `filename.lz4`. + * It is considered bad practice to rely on implicit output in scripts. + because the script's environment may change. + Always use explicit output in scripts. + `-c` ensures that output will be `stdout`. + Conversely, providing a destination name, or using `-m` + ensures that the output will be either the specified name, or `filename.lz4` respectively. Default behaviors can be modified by opt-in commands, detailed below. * `lz4 -m` makes it possible to provide multiple input filenames, which will be compressed into files using suffix `.lz4`. - Progress notifications are also disabled by default (use `-v` to enable them). + Progress notifications become disabled by default (use `-v` to enable them). This mode has a behavior which more closely mimics `gzip` command line, with the main remaining difference being that source files are preserved by default. * Similarly, `lz4 -m -d` can decompress multiple `*.lz4` files. @@ -81,8 +81,7 @@ In some cases, some options can be expressed using short command `-x` or long command `--long-word`. Short commands can be concatenated together. For example, `-d -c` is equivalent to `-dc`. -Long commands cannot be concatenated. -They must be clearly separated by a space. +Long commands cannot be concatenated. They must be clearly separated by a space. ### Multiple commands diff --git a/programs/lz4cli.c b/programs/lz4cli.c index 279aaf1..82f2fac 100644 --- a/programs/lz4cli.c +++ b/programs/lz4cli.c @@ -655,8 +655,9 @@ int main(int argc, const char** argv) if (!IS_CONSOLE(stdout)) { /* Default to stdout whenever stdout is not the console. - * Note : this policy is likely to change in the future, don't rely on it ! - * prefer using an explicit `-c` flag */ + * Note : this policy may change in the future, therefore don't rely on it ! + * To ensure `stdout` is explicitly selected, use `-c` command flag. + * Conversely, to ensure output will not become `stdout`, use `-m` command flag */ DISPLAYLEVEL(1, "Warning : using stdout as default output. Do not rely on this behavior: use explicit `-c` instead ! \n"); output_filename=stdoutmark; break; diff --git a/tests/Makefile b/tests/Makefile index 209a530..ddc6d1e 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -317,7 +317,7 @@ test-lz4-basic: lz4 datagen unlz4 lz4cat ! $(LZ4) -c --fast=-1 tmp-tlb-dg20K # lz4 should fail when fast=-1 # Test for #596 @echo "TEST" > tmp-tlb-test - $(LZ4) tmp-tlb-test + $(LZ4) -m tmp-tlb-test $(LZ4) tmp-tlb-test.lz4 tmp-tlb-test2 $(DIFF) -q tmp-tlb-test tmp-tlb-test2 @$(RM) tmp-tlb* |