From: Junio C Hamano
Instead of checking out unmerged entries, copy out the files from named stage. <number> must be between 1 and 3. + Note: --stage=all automatically implies --temp. +
++ Instead of copying the files to the working directory + write the content to temporary files. The temporary name + associations will be written to stdout.
When --temp is used (or implied by --stage=all) +git-checkout-index will create a temporary file for each index +entry being checked out. The index will not be updated with stat +information. These options can be useful if the caller needs all +stages of all unmerged entries so that the unmerged files can be +processed by an external merge tool.
+A listing will be written to stdout providing the association of +temporary file names to tracked path names. The listing format +has two variations:
++tempname TAB path RS +
+The first format is what gets used when --stage is omitted or +is not --stage=all. The field tempname is the temporary file +name holding the file content and path is the tracked path name in +the index. Only the requested entries are output.
++stage1temp SP stage2temp SP stage3tmp TAB path RS +
+The second format is what gets used when --stage=all. The three +stage temporary fields (stage1temp, stage2temp, stage3temp) list the +name of the temporary file if there is a stage entry in the index +or . if there is no stage entry. Paths which only have a stage 0 +entry will always be omitted from the output.
+In both formats RS (the record separator) is newline by default +but will be the null byte if -z was passed on the command line. +The temporary file names are always safe strings; they will never +contain directory separators or whitespace characters. The path +field is always relative to the current directory and the temporary +file names are always relative to the top level directory.
+If the object being copied out to a temporary file is a symbolic +link the content of the link will be written to a normal file. It is +up to the end-user or the Porcelain to make use of this information.
+