配方似乎忽略了循环内的条件答案

【问题标题】：Recipe seems to ignore condition inside loop配方似乎忽略了循环内的条件
【发布时间】：2014-09-28 03:05:33
【问题描述】：

我的制作文件中有这个食谱：

.PHONY: matlab                                         
matlab: $(matlab_files)                                
  set -x;for f in `echo "$^"`; do\                     
    base=`basename $$f`;\                              
    if [[ ! -f "$(matlab_dir_name)/$${base}" ]]; then\ 
      ln -s $$f $(matlab_dir_name)/$${base}; \         
    fi;\                                               
  done;set +x

也就是说，我想在创建链接之前检查链接是否存在。但是 if 测试似乎被忽略了。使用上面显示的调试选项，我得到以下几行：

+ for f in '`echo "MatlabD3PDImport/matlab/d3pd_export.m MatlabD3PDImport/matlab/matd3pd.m MatlabD3PDImport/matlab/net2py.m MatlabRingerTrain/matlab/cluster_size.m MatlabRingerTrain/matlab/create_cluster.m MatlabRingerTrain/matlab/getEffAtThres.m MatlabRingerTrain/matlab/getThresAndEff.m MatlabRingerTrain/matlab/scanparam.m MatlabRingerTrain/matlab/script_normal_train_offline.m MatlabRingerTrain/matlab/trainBinaryClassifier.m MatlabRingerTrain/matlab/trainRinger.m MatlabRingerTrain/matlab/xValidateBinaryClassifier.m"`'
++ basename MatlabRingerTrain/matlab/scanparam.m
+ base=scanparam.m
+ [[ ! -f matlab/scanparam.m ]]
+ ln -s MatlabRingerTrain/matlab/scanparam.m matlab/scanparam.m
ln: matlab/scanparam.m: File exists
+ for f in '`echo "MatlabD3PDImport/matlab/d3pd_export.m MatlabD3PDImport/matlab/matd3pd.m MatlabD3PDImport/matlab/net2py.m MatlabRingerTrain/matlab/cluster_size.m MatlabRingerTrain/matlab/create_cluster.m MatlabRingerTrain/matlab/getEffAtThres.m MatlabRingerTrain/matlab/getThresAndEff.m MatlabRingerTrain/matlab/scanparam.m MatlabRingerTrain/matlab/script_normal_train_offline.m MatlabRingerTrain/matlab/trainBinaryClassifier.m MatlabRingerTrain/matlab/trainRinger.m MatlabRingerTrain/matlab/xValidateBinaryClassifier.m"`'
++ basename MatlabRingerTrain/matlab/script_normal_train_offline.m
+ base=script_normal_train_offline.m
+ [[ ! -f matlab/script_normal_train_offline.m ]]
+ ln -s MatlabRingerTrain/matlab/script_normal_train_offline.m matlab/script_normal_train_offline.m
ln: matlab/script_normal_train_offline.m: File exists
+ for f in '`echo "MatlabD3PDImport/matlab/d3pd_export.m MatlabD3PDImport/matlab/matd3pd.m MatlabD3PDImport/matlab/net2py.m MatlabRingerTrain/matlab/cluster_size.m MatlabRingerTrain/matlab/create_cluster.m MatlabRingerTrain/matlab/getEffAtThres.m MatlabRingerTrain/matlab/getThresAndEff.m MatlabRingerTrain/matlab/scanparam.m MatlabRingerTrain/matlab/script_normal_train_offline.m MatlabRingerTrain/matlab/trainBinaryClassifier.m MatlabRingerTrain/matlab/trainRinger.m MatlabRingerTrain/matlab/xValidateBinaryClassifier.m"`'
++ basename MatlabRingerTrain/matlab/trainBinaryClassifier.m
+ base=trainBinaryClassifier.m
+ [[ ! -f matlab/trainBinaryClassifier.m ]]
+ ln -s MatlabRingerTrain/matlab/trainBinaryClassifier.m matlab/trainBinaryClassifier.m
ln: matlab/trainBinaryClassifier.m: File exists
+ for f in '`echo "MatlabD3PDImport/matlab/d3pd_export.m MatlabD3PDImport/matlab/matd3pd.m MatlabD3PDImport/matlab/net2py.m MatlabRingerTrain/matlab/cluster_size.m MatlabRingerTrain/matlab/create_cluster.m MatlabRingerTrain/matlab/getEffAtThres.m MatlabRingerTrain/matlab/getThresAndEff.m MatlabRingerTrain/matlab/scanparam.m MatlabRingerTrain/matlab/script_normal_train_offline.m MatlabRingerTrain/matlab/trainBinaryClassifier.m MatlabRingerTrain/matlab/trainRinger.m MatlabRingerTrain/matlab/xValidateBinaryClassifier.m"`'
++ basename MatlabRingerTrain/matlab/trainRinger.m
+ base=trainRinger.m
+ [[ ! -f matlab/trainRinger.m ]]
+ ln -s MatlabRingerTrain/matlab/trainRinger.m matlab/trainRinger.m
ln: matlab/trainRinger.m: File exists
+ for f in '`echo "MatlabD3PDImport/matlab/d3pd_export.m MatlabD3PDImport/matlab/matd3pd.m MatlabD3PDImport/matlab/net2py.m MatlabRingerTrain/matlab/cluster_size.m MatlabRingerTrain/matlab/create_cluster.m MatlabRingerTrain/matlab/getEffAtThres.m MatlabRingerTrain/matlab/getThresAndEff.m MatlabRingerTrain/matlab/scanparam.m MatlabRingerTrain/matlab/script_normal_train_offline.m MatlabRingerTrain/matlab/trainBinaryClassifier.m MatlabRingerTrain/matlab/trainRinger.m MatlabRingerTrain/matlab/xValidateBinaryClassifier.m"`'
++ basename MatlabRingerTrain/matlab/xValidateBinaryClassifier.m
+ base=xValidateBinaryClassifier.m
+ [[ ! -f matlab/xValidateBinaryClassifier.m ]]
+ ln -s MatlabRingerTrain/matlab/xValidateBinaryClassifier.m matlab/xValidateBinaryClassifier.m
ln: matlab/xValidateBinaryClassifier.m: File exists
+ set +x

为什么 shell 会忽略 if 测试？

【问题讨论】：

标签： shell loops if-statement gnu-make

【解决方案1】：

-f FILE 检查文件是否存在并且是否为常规文件。要在测试中包含符号链接，请使用 -h/-L（仅限符号链接）或 -e（所有文件）。

if [[ ! -e "$(matlab_dir_name)/$${base}" ]]; then

【讨论】：

谢谢，我刚刚发现错误与符号链接有关，因为 matlab 也无法运行符号链接。我将其更改为硬链接，-f test 和 matlab 都可以识别该文件。幸运的是，您的回答只是提供了关闭线程所缺少的所有信息。