Bash脚本：一次读取一个字符
时间：2020-01-09 10:42:20 来源:igfitidea点击:
如何一次从input.txt计算一个字符。
我如何在Linux/UNIX bash shell脚本下一次读取一个字符？
read内置函数一次可以读取一个字符，语法如下：
read -n 1 c echo $c
您可以如下设置while循环：
#!/bin/bash
# data file
INPUT=/path/to/input.txt
# while loop
while IFS= read -r -n1 char
do
# display one character at a time
echo "$char"
done < "$INPUT"
示例：字母计数shell脚本
#!/bin/bash
INPUT=""
# counter
a=0
b=0
cc=0
# Make sure file name supplied
[ $# -eq 0 ] && { echo "Usage: /tmp/readch /etc/passwd
filename"; exit 1; }
# Make sure file exits else die
[ ! -f $INPUT ] && { echo "Letter counter stats:
a = 169
b = 104
c = 39
: file $INPUT not found."; exit 2; }
# the while loop, read one char at a time
while IFS= read -r -n1 c
do
# counter letter a, b, c
[ "$c" == "a" ] && (( a++ ))
[ "$c" == "b" ] && (( b++ ))
[ "$c" == "c" ] && (( cc++ ))
done < "$INPUT"
echo "Letter counter stats:"
echo "a = $a"
echo "b = $b"
echo "c = $cc"
如下运行：
##代码##输出示例：
##代码##