當在所有檔案中找到模式時，while回圈會中斷嗎？

下面的代碼在多個檔案（以 snp_search.txt 結尾的檔案的 $file 變數）中搜索一組模式（包含在 $snps 變數中）并輸出一個長串列，說明每個 snp 是否在每個檔案中。

目的是找到所有檔案中的幾個 SNP 。

有沒有辦法將下面的代碼嵌入到 while 回圈中，以便它繼續運行，直到它找到所有檔案中的 SNP 并在它找到時中斷？否則我必須手動檢查日志檔案。

for snp in $snplist; do
   for file in *snp_search.txt; do

     if grep -wq "$snp" $file; then
       echo "${snp} was found in $file" >> ${date}_snp_search.log; else
       echo "${snp} was NOT found in $file" >> ${date}_snp_search.log
     fi
   done
done

uj5u.com熱心網友回復：

您可以使用grep搜索所有檔案。如果檔案名不包含換行符，您可以直接計算匹配檔案的數量：

#! /bin/bash
files=(*snp_search.txt)
count_files=${#files[@]}
for snp in $snplist ; do
    count=$(grep -wl "$snp" *snp_search.txt | wc -l)
    if ((count == count_files)) ; then
        break
    fi
done

對于包含換行符的檔案名，您可以為每個 $snp 輸出不帶檔案名的第一個匹配行并計算行數：

count=$(grep -m1 -hw "$snp" *snp_search.txt | wc -l)

uj5u.com熱心網友回復：

假設：

• 輸入檔案的一行中可能存在多個 SNP
• 將列印所有檔案中存在的所有SNP的串列（OP 提到了矛盾的陳述：vs ）find several SNPs that are in all of the filesbreak when one SNP is found in all files

示例輸入（如果 OP 使用示例資料更新問題，則會更新）：

$ cat snp.dat
ABC
DEF
XYZZ

$ cat 1.snp.search.txt

ABCD-XABC
someABC_stuff
ABC-
de-ABC-
de-ABC
DEFG
zDEFG
.DEF-xyz
abc-DEF
abc-DEF-ABC-xyz

$ cat 2.snp.search.txt
ABC

一個GNU awk需要單次遍歷每個輸入檔案的想法：

awk '
FNR==NR { snps[$1]=0; next }                        # load 1st file into array; initialize counter (of files containing this snp) to 0

FNR==1  { filecount                                 # 1st line of 2nd-nth files: increment counter of number of filds
          delete to_find                            # delete our to_find[] array
          for (snp in snps)                         # make a copy of our master snps[] array ...
               to_find[snp]                         # storing copy in to_find[] array
        }

        { for (snp in to_find) {                    # loop through list of snps 
              if ($0 ~ "\\y" snp "\\y") {           # if current line contains a "word" match on the current snp ...
                 snps[snp]                          # increment our snp counter (ie, number of files containing this snp)
                 delete to_find[snp]                # no longer need to search current file for this particular snp
#                break                              # if line can only contain 1 snp then uncomment this line
              }
          }

          for (snp in to_find)                      # if we still have an snp to find then ...
              next                                  # skip to next line else ...
          nextfile                                  # skip to next file
        }

END     { PROCINFO["sorted_in"]="@ind_str_asc"
          for (snp in snps)
              if (snps[snp] == filecount)
                 printf "The SNP %s was found in all files\n", snp
        }
' snp.dat *.snp.search.txt 

筆記：

• GNU awk is required for the PROCINFO["sorted_in"]="@ind_str_asc" option to sort the snps[] array indices; if GNU awk is not available, or ordering of output messages is not important, then this command can be removed from the code
• since we only process each input file once we will print all SNPs that show up in all files (ie, we won't know if a SNP exists in all files until we've processed the last file so might as well print all SNPs that exist in all fiels)
• should be faster than processes that require multiple scans of each input file (especially for larger files and/or a large number of SNPs)

This generates:

The SNP ABC was found in all files

標籤：linux 猛击 循环 for循环 while 循环

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