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本帖最后由 seesea2517 于 2014-03-28 15:12 编辑
回复 1# ccnuzxg
是啊,<() 这个语法是bash特性。用临时文件就好了呗。
quote 标签会解释出表情来,看来还是code标签好啊。- Things bash has that sh does not:
- long invocation options
- [+-]O invocation option
- -l invocation option
- `!' reserved word to invert pipeline return value
- `time' reserved word to time pipelines and shell builtins
- the `function' reserved word
- the `select' compound command and reserved word
- arithmetic for command: for ((expr1 ; expr2; expr3 )); do list; done
- new ...' and $"..." quoting
- the $(...) form of command substitution
- the $(<filename) form of command substitution, equivalent to
- $(cat filename)
- the ${#param} parameter value length operator
- the ${!param} indirect parameter expansion operator
- the ${!param*} prefix expansion operator
- the ${param:offset[:length]} parameter substring operator
- the ${param/pat[/string]} parameter pattern substitution operator
- expansions to perform substring removal (${p%[%]w}, ${p#[#]w})
- expansion of positional parameters beyond $9 with ${num}
- variables: BASH, BASH_VERSION, BASH_VERSINFO, UID, EUID, REPLY,
- TIMEFORMAT, PPID, PWD, OLDPWD, SHLVL, RANDOM, SECONDS,
- LINENO, HISTCMD, HOSTTYPE, OSTYPE, MACHTYPE, HOSTNAME,
- ENV, PS3, PS4, DIRSTACK, PIPESTATUS, HISTSIZE, HISTFILE,
- HISTFILESIZE, HISTCONTROL, HISTIGNORE, GLOBIGNORE, GROUPS,
- PROMPT_COMMAND, FCEDIT, FIGNORE, IGNOREEOF, INPUTRC,
- SHELLOPTS, OPTERR, HOSTFILE, TMOUT, FUNCNAME, histchars,
- auto_resume
- DEBUG trap
- ERR trap
- variable arrays with new compound assignment syntax
- redirections: <>, &>, >|, <<<, [n]<&word-, [n]>&word-
- prompt string special char translation and variable expansion
- auto-export of variables in initial environment
- command search finds functions before builtins
- bash return builtin will exit a file sourced with `.'
- builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t.
- export -n/-f/-p/name=value, pwd -L/-P,
- read -e/-p/-a/-t/-n/-d/-s/-u,
- readonly -a/-f/name=value, trap -l, set +o,
- set -b/-m/-o option/-h/-p/-B/-C/-H/-P,
- unset -f/-v, ulimit -i/-m/-p/-q/-u/-x,
- type -a/-p/-t/-f/-P, suspend -f, kill -n,
- test -o optname/s1 == s2/s1 < s2/s1 > s2/-nt/-ot/-ef/-O/-G/-S
- bash reads ~/.bashrc for interactive shells, $ENV for non-interactive
- bash restricted shell mode is more extensive
- bash allows functions and variables with the same name
- brace expansion
- tilde expansion
- arithmetic expansion with $((...)) and `let' builtin
- the `[[...]]' extended conditional command
- process substitution
- aliases and alias/unalias builtins
- local variables in functions and `local' builtin
- readline and command-line editing with programmable completion
- command history and history/fc builtins
- csh-like history expansion
- other new bash builtins: bind, command, compgen, complete, builtin,
- declare/typeset, dirs, enable, fc, help,
- history, logout, popd, pushd, disown, shopt,
- printf
- exported functions
- filename generation when using output redirection (command >a*)
- POSIX.2-style globbing character classes
- POSIX.2-style globbing equivalence classes
- POSIX.2-style globbing collating symbols
- egrep-like extended pattern matching operators
- case-insensitive pattern matching and globbing
- variable assignments preceding commands affect only that command,
- even for builtins and functions
- posix mode and strict posix conformance
- redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr,
- /dev/tcp/host/port, /dev/udp/host/port
- debugger support, including `caller' builtin and new variables
- RETURN trap
- the `+=' assignment operator
- Things sh has that bash does not:
- uses variable SHACCT to do shell accounting
- includes `stop' builtin (bash can use alias stop='kill -s STOP')
- `newgrp' builtin
- turns on job control if called as `jsh'
- $TIMEOUT (like bash $TMOUT)
- `^' is a synonym for `|'
- new SVR4.2 sh builtins: mldmode, priv
- Implementation differences:
- redirection to/from compound commands causes sh to create a subshell
- bash does not allow unbalanced quotes; sh silently inserts them at EOF
- bash does not mess with signal 11
- sh sets (euid, egid) to (uid, gid) if -p not supplied and uid < 100
- bash splits only the results of expansions on IFS, using POSIX.2
- field splitting rules; sh splits all words on IFS
- sh does not allow MAILCHECK to be unset (?)
- sh does not allow traps on SIGALRM or SIGCHLD
- bash allows multiple option arguments when invoked (e.g. -x -v);
- sh allows only a single option argument (`sh -x -v' attempts
- to open a file named `-v', and, on SunOS 4.1.4, dumps core.
- On Solaris 2.4 and earlier versions, sh goes into an infinite
- loop.)
- sh exits a script if any builtin fails; bash exits only if one of
- the POSIX.2 `special' builtins fails
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