WHICH(1) General Commands Manual WHICH(1)
NAME
which - locate a command
#就是用来找一个命令的绝对路径
SYNOPSIS
which [-a] filename ...
DESCRIPTION
which returns the pathnames of the files (or links) which would be executed in the current environment, had its arguments been given as com‐
mands in a strictly POSIX-conformant shell. It does this by searching the PATH for executable files matching the names of the arguments. It
does not follow symbolic links.
OPTIONS
-a print all matching pathnames of each argument
EXIT STATUS
0 if all specified commands are found and executable
1 if one or more specified commands is nonexistent or not executable
2 if an invalid option is specified
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WHEREIS(1) User Commands WHEREIS(1)
NAME
whereis - locate the binary, source, and manual page files for a command
#寻找一个命令的绝对路径，源代码，用户手册
SYNOPSIS
whereis [-bmsu] [-BMS directory... -f] filename...
DESCRIPTION
whereis locates source/binary and manuals sections for specified files. The supplied names are first stripped of leading pathname compo‐
nents and any (single) trailing extension of the form .ext, for example, .c. Prefixes of s. resulting from use of source code control are
also dealt with. whereis then attempts to locate the desired program in a list of standard Linux places.
OPTIONS
-b Search only for binaries.
#相当于 which ls
-m Search only for manual sections.
-s Search only for sources.
以下三个选项用来改变相应的搜索路径
-B Change or otherwise limit the places where whereis searches for binaries.
-M Change or otherwise limit the places where whereis searches for manual sections.
-S Change or otherwise limit the places where whereis searches for sources.
-u Search for unusual entries. A file is said to be unusual if it does not have one entry of each requested type. Thus
`whereis -m -u *‘ asks for those files in the current directory which have no documentation.
-f Terminate the last directory list and signals the start of file names, and must be used when any of the -B, -M, or -S options are
used.
EXAMPLE
Find all files in /usr/bin which are not documented in /usr/man/man1 with source in /usr/src:
example% cd /usr/bin
example% whereis -u -M /usr/man/man1 -S /usr/src -f *
FILES
/{bin,sbin,etc}
/usr/{lib,bin,old,new,local,games,include,etc,src,man,sbin,
X386,TeX,g++-include}
/usr/local/{X386,TeX,X11,include,lib,man,etc,bin,games,emacs}
SEE ALSO
chdir(2V)
BUGS
Since whereis uses chdir(2V) to run faster, pathnames given with the -M, -S, or -B must be full; that is, they must begin with a `/‘.
whereis has a hard-coded path, so may not always find what you‘re looking for.
AVAILABILITY
The whereis command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
util-linux July 2009 WHEREIS(1)