linux source shell脚本显示找不到文件

例子： 

[root@localhost osc]# sh a.sh 
a.sh: line 4: source: 1.sh: file not found
[root@localhost osc]# cat a.sh 
#!/bin/bash
cd /data/osc/bin/
if [ -f 1.sh ];then
source 1.sh
fi

刚开始，还觉得权限问题，而后给权限，但结果仍是同样

man source ,找到缘由了。source时找filename的问题。

source 命令找filename是在当前的shell环境下找的，若是没有反斜线，就在path中找，若是没有就没有。

source filename [arguments]
              Read  and  execute commands from filename in the current shell environment and return the exit status of the last command exe-
              cuted from filename.  If filename does not contain a slash, file names in PATH are used to find the directory containing file-
              name.   The  file  searched  for  in  PATH  need  not be executable.  When bash is not in posix mode, the current directory is
              searched if no file is found in PATH.  If the sourcepath option to the shopt builtin command is turned off, the  PATH  is  not
              searched.   If  any  arguments  are  supplied, they become the positional parameters when filename is executed.  Otherwise the
              positional parameters are unchanged.  The return status is the status of the last command exited within the script  (0  if  no
              commands are executed), and false if filename is not found or cannot be read.

以下方式均可以：

一、将脚本所在的目录加到PATH中

二、加上相对路径或绝对路径

三、就算是当前目录也得加./