if!type"$foobar_command_name"> /dev/null;then# install foobar here,or poping up some warning messagesfi references: http://stackoverflow.com/questions/7522712/how-to-check-if-command-exists-in-a-shell-script http://stackoverflow.com/questions/592620/how-to-check-if-a-program-exists-from-a...
And finally, we taught you how to make life a little better for you. We’ve taught you how to write a complete bash script to check if a file exists multiple times at the same time. You won’t have to trouble yourself when you look for a file! You can wait for the program to r...
shell 使用哪个bash命令检查程序是否存在(即使是别名)？test-L选项应该可以使用：
First this program will print “Start program”, then the IF statement will check if the conditional expression[[ $1 -eq 4 ]]is true. It will only be true if you provide4as the first argument to the script. If the conditional expression if true then it will execute the code in betwee...
" ## Check whether a filename was entered if [ -n "$filename" ] then if [ $verbose -gt 0 ] then printf "Filename is %s\n" "$filename" fi else if [ $verbose -gt 0 ] then printf "No filename entered\n" >&2 fi exit 1 fi ## Check whether file exists if [ -f "$...
if [ -f "$file" ] ; then newfile=`echo "$file" | sed "s/${OLD}/${NEW}/g"` if [ -f "$newfile" ]; then echo "ERROR: $newfile exists already" else echo "renaming $file to $newfile ..." mv "$file" "$newfile" ...
If you add set-o errexitto your script, from that point forward it will abort the execution if any command exists with a code!= 0. Buterrexitisn't used when executing functions inside anifcondition, so instead of remembering that exception, I rather do explicit error handling. ...
("macho", rom_buf, rom_buf_size, rom_base, as); ret = true; uint64_t load_extra_offset = high_addr_temp; uint64_t ramdisk_address = load_extra_offset; gsize ramdisk_size = 0; // load ramdisk if exists if (info->initrd_filename) { uint8_t* ramdisk_data = NULL; if (g_...
To test if a file exists. -f To test if a given file is a regular file. -d To test if the file is a directory. -b To test if the file is a block device. -s To test if the file is not zero sizes. -L To test if the file is a symbolic link. -S To test if the file...
Test if File Exists Send Email Example Get Parse Current Date Wait Command Sleep Command Create and Execute First BASH Program: You can run bash script from the terminal or by executing any bash file. Run the following command from the terminal to execute a very simple bash statement. The ou...