In the script, thecatcommand is executed using command substitution. The output ofcat file1.txtreplaces the command, and theforloop iterates through the command’s output and prints it to the standard output using theprintfcommand. #!/bin/bashprintf"Program prints the lines of a file\n\n...
# Loop from 0-100 (no variable support). for i in {0..100}; do printf '%s\n' "$i" done 循环遍历可变数字范围 替代seq。 # Loop from 0-VAR. VAR=50 for ((i=0;i<=VAR;i++)); do printf '%s\n' "$i" done 循环数组 arr=(apples oranges tomatoes) # Just elements. for elemen...
break 2 ## break out of both while and for loops elif [ $RANDOM -lt 10000 ] then printf '"' break ## break out of the while loop fi done done echo 继续 在循环内部, continue命令通过传递任何剩余命令,立即开始循环的新迭代: for n in {1..9} ## See Brace expansion in Chapter 4 d...
Any array variable contains a list of data that can be iterated very easily by usingfor-inloop. The following example shows the use offor-inloop to read an array of string data. Here, each array value will fetch in the variable,$languageand print a message based on language in each ite...
# Usage: lines_loop "file" count=0 while IFS= read -r _; do ((count++)) done < "$1" printf '%s\n' "$count" } 1. 2. 3. 4. 5. 6. 7. 8. 用法示例: $ lines ~/.bashrc 48 $ lines_loop ~/.bashrc 48 1. 2.
while read -r line || [[ $line ]]; do my_array+=("$line") done < my_file 将整个文件读入数组(Bash版本4x及更高版本) readarray -t my_array < my_file 或者 mapfile -t my_array < my_file 然后 for line in "${my_array[@]}"; do # process the lines done 了解shell内置...
‘for’ loop will iterate each filename from the command output and store it in the variable $filename that will print later. Here, $n variable is used to display the file number. forloop4.sh n=1 for filename in `ls *.txt` do echo "File No-$n : $filename" ((n++)) done ...
# The error file is the first on backtrace list: # Exploding backtrace on newlines mem=$IFS IFS=' ' # # Substring: I keep only the carriage return # (others needed only for tabbing purpose) IFS=${IFS:0:1} local lines=( $_backtrace ) IFS=$mem error_file="" if test -n"${lines...
awk 'FRN == RN {wordsArr[++wordsCount] = $0} # read file1 lines into array FRN != RN && /example/ { # read file2 line matching regExp /example/ for (i in wordsArr) { # scan all words in array if ($0 ~ wordsArr[i]) { # if a word matched in current line print; # ...
forfruitinApple Banana Cherry;doecho"I love$fruit";done# Output:# I love Apple# I love Banana# I love Cherry Bash Copy In this example, the ‘for’ loop iterates over the list of fruits (Apple, Banana, Cherry). For each iteration, it executes theechocommand to print out a statement...